Indian Navy Developments & Discussions

[Blood+]

Having four CIWS and still having blind zones

Typical Indian ingenuity.

 

[Nutcracker]

So it's time for what no-one was waiting for

Okay, let's start with this

So as usual, Corvus's accurate in his assesment...the biggest issue seems to be the tracking part of the CIWS. There are multiple smaller issues like mounting radar and gun on same TE (Traverse - Elevation) mechanism eliminates thing like out-of-sync gun & radar turret, the stacking tolerances of both turret and backlash error of four actuation mechanism as both your gun and radar are now mechanically boresighted. You also have the added benefit of redundancy. Not to mention the fact that AO-18s generally have a reputation of high dispersion compared to other systems like Phalanx or Goalkeeper.
But just to keep things fair, I'll ignore all those and dive into radars only.

Before I start just a basic 101 of radar; the smaller the wavelength the more accurate a radar would get and the larger it gets the longer it'd be able to see. That's the reason why almost all targetting radars for CIWS are in Ka-X range (0.75-3.8cm), a non exhaustive list...
• MR-123 or Bass Tilt (the standard Russian radar for AK-630) = X
• Lynx U2 (what we use for AK-630) = X or Ku
[Side note; isn't Lynx U2 a copy of Thales TMX/EO?]
• EL/M-2221 (also used for AK-630, Barak-1) = X and Ka
• Goalkeeper = X and K
• Mk-15 Phalanx = Ku
• Type 730 = Ku

1. Veer Class
View attachment 19458
• Radar is accurate (X-Ku) but a single radar is used to cover almost 300° (not 360°) of sector; i.e, both starboard and port
• Isn't there an obvious blind zone towards the stern as the mast comes in LoS of the radar?

2. Khukri Class
• Pretty much the exact same arrangement of Veer is used on Khukri Class; one with Lynx and other with Bass Tilt.

3. Kora Class
View attachment 19459
• One uses Bass Tilt and rest all uses Lynx U2, again one single radar controlling everything. And again the mast preventing direct rearwards LoS.

For these three specific ships, I don't know how they're going to deal with a missile having good evasive maneuvers or waypoint navigation capabilities. An AShM is launched from 300km, coming straight towards the bow the missile starts maneuvering 7-8km (outside the range of 30x165mm ammo) away from it and comes back in from the stern side.
BrahMos has been doing S-maneuvers at Mach 2+ since last two decades, just to get an idea how easy it's to perform these kind of maneuvers.

From here things start to improve a bit
4. Kamorta Class
View attachment 19461
• You've two separate radars to cover almost 360° so simultaneous attack from both flanks can be countered. Also there isn't that usual blind zone in stern.
• But here's too there's something that I've questions about. See the raised section of superstructure (Orange) just in front of AK-630 guns. Isn't that going to limit the arc of fire of the gun, especially if an AShM comes head-on from bow?

5. Talwar Class...now this is a proper circus
View attachment 19491
View attachment 19492
• Three different flights and all is bit different. And then you've some that have gone through refit. But more or less it's either Kashtan or AK-630 with mix of radars.
• The ones with Kashtan are funny, because they're the epitome of CIWS but we don't have ammo for them.
• As for others, you've a typical set-up of 2x AK-630 but guided by a single Lynx U2 or 5P-10E radar in front. Again weird as the mast block LoS of rear. Frigates but still has the same problem as Veer class corvettes.
• Four rounds things may look like MR-123 (the radar used for AK-630) but sadly those are MR-90, the illumination radar needed for Shtil-1 SAMs. They look almost identical.

6. Shivalik Class
View attachment 19490
• Should perhaps be the best CIWS set-up. 16x Barak-1 and one AK-630 on each side with two EL/M-2221.
• But here too the mounting position of the guns seem suboptimal as the arc of firing gets blocked in front by superstructure

7. Brahmaputra Class
• One active, one already seen multiple incidents and one completely out of service. No point discussing these but generally you'd have two Lynx U2 directing four AK-630s. Quite good for this old ships.

8. Rajput Class
Even the latest of this is more than 35 years old and decommissioning already started so leaving it.

9. Delhi Class
View attachment 19472
• As usual, the forward arc of fire gets blocked by mast for radar.
• Pretty similar to Shivaliks but on paper this should perhaps be the best integrated CIWS we ever had apart from obviously Kashtans. 16x Barak-1 and one AK-630 on each side guided by their own fire control radar, all mounted pretty close to each other. Nice

And from here things take an interesting turn as we move up

10. Kolkata - Vishakapatnam Class
View attachment 19474
• Obviously sub optimal placement; instead of two cluster of two one could easily go with one each on bow-starboard-stern-port, same amount of guns but improved overlapping arcs of fire. Here too, the guns are mounted in such a way the the superstructure interferes not just in front but also in rear. In case of mounting near the hangars (like say Kamorta) only the frontal arc was obscured but here the rear too gets interfered.
• But perhaps most important, there isn't any fire director now. Everything is controlled by the MF-STAR which is perfectly fine except for the band; it's S-band. MF-STAR is used by Koreans and Israelis too but only we use it for CIWS.
No doubt, it can definitely be used for this role but as you move from Ku to S your precision decreases. 2.5 to 3.8cm now becomes 7.5 to 15cm, definitely a difference that you can feel with next gen low RCS missiles like LRASM.

11. Vikrant
Again exactly the same case as P-15s, S-band radar being used for fire control.


As always, everything's just my brainrot shitposting so proceed with caution. Feel free to correct wherever needed. Infact I'm hoping that I'm proven wrong.

All this complex shit..
our naval designers could've just ate crayons(they did nevertheless) and put two guns diagonally across the ship with independent radars. 99% problems might've been solved I guess.

 

[shiphone]

you might be able to have a check of those EO device near the AK630s on these latest IN main warships. ... they controled the guns(including the oto76 on P15A/B P17A) not the MF-STAR.

and you might have to have an another check of the SEARCH radars for the close-in defence on this generation of IN warships as well...is there any?

-------------
the Pozitiv-ME1.2 on the hangar

 

[Ayan Barat]

Typical Indian ingenuity.

That would be CRN-91
They took the whole damn turret of a BMP-2 and mounted it. How would you fire it? Exactly like a BMP, crawl inside the turret, sit on the commander's chair and fire

put two guns diagonally across the ship with independent radars. 99% problems might've been solved I guess.

If you ask me for a better design.

Nothing complicated or state of the art, just using some ingenuity.
• gun 1 would easily cover almost 270°
• gun 2 and 4 are mounted on extended platforms. By extending just a meter or so you can get an uninterrupted 180° firing arc, overlapping with both the bow and stern gun's. This platform can even be made retractable so that you don't have any issues while docking in port
• gun 3 is simple, no brainer
• if you've money then you can easily replace station 1 and 3 with a missile launchers. Anything, even 20-30 VSHORADs bunched together

you might be able to have a check of those EO device near the AK630s on these latest main IN warships. ... they controled the guns(including the oto76 on P15A/B P17A) not the MF-STAR.

• For EL/M-2221, Lynx U2 and MR-123 you've EO included in the targetting radar
• For the one's using MF-STAR, a separate EO ball is added near the AK-630 gun mount to compensate for lack of proper Fire Control System. You can't engage a cruise missile with these kinds of improvised EO set-ups, these come handy when you want to manually fire the gun at surface targets like those poor pirates

and you might have to have another check of the SEARCHING radars for the close defence on this generation of IN warships as well...is there any?

Nope, there isn't. For say Kolkata, you only have these
• APARNA (Indigenized Garpun); primarily for navigation, 76mm main gun targetting and AShM targetting. Though theoretically can be used for CIWS too.
• Ajanta - Ellora; EW/ESM/ECM...I don't think there's any way of using these for targeting
• a navigation radar, typically Scanter; again can't use for CIWS
• an air search radar like LW-08 (or the MR352 Pozitiv-M1.2 you posted); wavelength is too large to accurately aim
• MF-STAR; the only you've that can aim CIWS with reasonable accuracy.

It's bit confusing for me that why a S and a D band radars are used. Generally you'd want bit "gap" between the frequencies to cover a broader spectrum, whereas S and D are adjacent.
Like Zumwalt was supposed to use a S band for volume search and a X band for precise targetting. Or the Sachsen Class with X and S band. Type 45 destroyer too have this adjacent band thing going on (S and L) but they've Phalanx, with their own targetting radars.

 

[vampyrbladez]

INS Tushil passing through the Tower Bridge.

 

[shiphone]

but they've Phalanx, with their own targetting radars.

and the search radar


-----------------------

BTW... the MR352 Pozitiv-M1.2--- X band, the typical short range /quick reaction serch radar

 

[shiphone]

INS Tushil passing through the London Bridge.

the tower bridge...the London bridge is right behind the ship

 

[Corvus Splendens]

Having four CIWS and still having blind zones

Easily solved by getting rid off the RBU launchers at front. And placing at least 1 Ak-630 there. And another one at the back overlooking the landing pad/bay.

Suboptimal placement of 4 units that are already sitting too low. The ship is totally CIWS blind from a good 30-40 degree frontal cone, and semi blind from sea skimming low missiles coming from the rear dead on. Thanks to that spoiler/lip containing the bay door mechanism.

 

[Ayan Barat]

Easily solved by getting rid off the RBU launchers at front.

Lol, lmao even
Those are not going anywhere. Some 30-40 years later when we'd have our nuclear powered cruiser with a rail gun, then also you'd find those RBUs.

Suboptimal placement of 4 units that are already sitting too low. The ship is totally CIWS blind from a good 30-40 degree frontal cone, and semi blind from sea skimming low missiles coming from the rear dead on. Thanks to that spoiler/lip containing the bay door mechanism.

Not to mention the fact that AK-630s already have issues with gun depression. In Phalanx or even Goalkeeper (pretty much the Western analogue to it) the gun goes as low as -25°. For AK-630 it's just -12°.

 

[Blood+]

That would be CRN-91
They took the whole damn turret of a BMP-2 and mounted it. How would you fire it? Exactly like a BMP, crawl inside the turret, sit on the commander's chair and fire

Man, why did you have to remind me of that abomination of all things?? Life's already pretty shite as it is.

If you ask me for a better design.
View attachment 19496
Nothing complicated or state of the art, just using some ingenuity.
• gun 1 would easily cover almost 270°
• gun 2 and 4 are mounted on extended platforms. By extending just a meter or so you can get an uninterrupted 180° firing arc, overlapping with both the bow and stern gun's. This platform can even be made retractable so that you don't have any issues while docking in port
• gun 3 is simple, no brainer
• if you've money then you can easily replace station 1 and 3 with a missile launchers. Anything, even 20-30 VSHORADs bunched together

Or just do it like this -

Or better still, place them on overhangs jutting out of the superstructure, much like your in your sketch but at the four corners rather than two amidships.

 

[vampyrbladez]

Easily solved by getting rid off the RBU launchers at front. And placing at least 1 Ak-630 there. And another one at the back overlooking the landing pad/bay.
View attachment 19503View attachment 19499
Suboptimal placement of 4 units that are already sitting too low. The ship is totally CIWS blind from a good 30-40 degree frontal cone, and semi blind from sea skimming low missiles coming from the rear dead on. Thanks to that spoiler/lip containing the bay door mechanism.
View attachment 19501

The RBU 6000 is more of a hardkill anti torpedo measure than a proper ASW.

With the Nilgiri Class receiving the DART/STRALES 76mm guided ammunition as part of the upgraded 76/62 mm SRGM, the main gun can now be used in CIWS roles with the MF-STAR acting as the FCR.

 

[Blood+]

Easily solved by getting rid off the RBU launchers at front. And placing at least 1 Ak-630 there. And another one at the back overlooking the landing pad/bay.

Not gonna happen and not really necessary, either. Just construct overhangs at the four corners of the superstructure and place the CIWS on those.

 

[shiphone]

the proper FCR is always needed...again, we don't think MF-STAR can work like this espeically in Close-in air defece Scenario.

----------

 

[shiphone]

something off topic...
an interesting GIF I saved earlier this week... is this the perfect layout of AK630s on a combat vessle? lol...
you see...the salvo mode is the real choice in close-in AD combat operation with AK630 guns... as the assessment revealing, normally the two guns need firing 6-7 seconds to create a effective barrage for interception. but again, the Projectile dispersion is not ideal so the interception probability against the sub sonic missiles is around 60-70%

 

[shade2]

So it's time for what no-one was waiting for

Okay, let's start with this

So as usual, Corvus's accurate in his assesment...the biggest issue seems to be the tracking part of the CIWS. There are multiple smaller issues like mounting radar and gun on same TE (Traverse - Elevation) mechanism eliminates thing like out-of-sync gun & radar turret, the stacking tolerances of both turret and backlash error of four actuation mechanism as both your gun and radar are now mechanically boresighted. You also have the added benefit of redundancy. Not to mention the fact that AO-18s generally have a reputation of high dispersion compared to other systems like Phalanx or Goalkeeper.
But just to keep things fair, I'll ignore all those and dive into radars only.

Before I start just a basic 101 of radar; the smaller the wavelength the more accurate a radar would get and the larger it gets the longer it'd be able to see. That's the reason why almost all targetting radars for CIWS are in Ka-X range (0.75-3.8cm), a non exhaustive list...
• MR-123 or Bass Tilt (the standard Russian radar for AK-630) = X
• Lynx U2 (what we use for AK-630) = X or Ku
[Side note; isn't Lynx U2 a copy of Thales TMX/EO?]
• EL/M-2221 (also used for AK-630, Barak-1) = X and Ka
• Goalkeeper = X and K
• Mk-15 Phalanx = Ku
• Type 730 = Ku

1. Veer Class
View attachment 19458
• Radar is accurate (X-Ku) but a single radar is used to cover almost 300° (not 360°) of sector; i.e, both starboard and port
• Isn't there an obvious blind zone towards the stern as the mast comes in LoS of the radar?

2. Khukri Class
• Pretty much the exact same arrangement of Veer is used on Khukri Class; one with Lynx and other with Bass Tilt.

3. Kora Class
View attachment 19459
• One uses Bass Tilt and rest all uses Lynx U2, again one single radar controlling everything. And again the mast preventing direct rearwards LoS.

For these three specific ships, I don't know how they're going to deal with a missile having good evasive maneuvers or waypoint navigation capabilities. An AShM is launched from 300km, coming straight towards the bow the missile starts maneuvering 7-8km (outside the range of 30x165mm ammo) away from it and comes back in from the stern side.
BrahMos has been doing S-maneuvers at Mach 2+ since last two decades, just to get an idea how easy it's to perform these kind of maneuvers.

From here things start to improve a bit
4. Kamorta Class
View attachment 19461
• You've two separate radars to cover almost 360° so simultaneous attack from both flanks can be countered. Also there isn't that usual blind zone in stern.
• But here's too there's something that I've questions about. See the raised section of superstructure (Orange) just in front of AK-630 guns. Isn't that going to limit the arc of fire of the gun, especially if an AShM comes head-on from bow?

5. Talwar Class...now this is a proper circus
View attachment 19491
View attachment 19492
• Three different flights and all is bit different. And then you've some that have gone through refit. But more or less it's either Kashtan or AK-630 with mix of radars.
• The ones with Kashtan are funny, because they're the epitome of CIWS but we don't have ammo for them.
• As for others, you've a typical set-up of 2x AK-630 but guided by a single Lynx U2 or 5P-10E radar in front. Again weird as the mast block LoS of rear. Frigates but still has the same problem as Veer class corvettes.
• Four rounds things may look like MR-123 (the radar used for AK-630) but sadly those are MR-90, the illumination radar needed for Shtil-1 SAMs. They look almost identical.

6. Shivalik Class
View attachment 19490
• Should perhaps be the best CIWS set-up. 16x Barak-1 and one AK-630 on each side with two EL/M-2221.
• But here too the mounting position of the guns seem suboptimal as the arc of firing gets blocked in front by superstructure

7. Brahmaputra Class
• One active, one already seen multiple incidents and one completely out of service. No point discussing these but generally you'd have two Lynx U2 directing four AK-630s. Quite good for this old ships.

8. Rajput Class
Even the latest of this is more than 35 years old and decommissioning already started so leaving it.

9. Delhi Class
View attachment 19472
• As usual, the forward arc of fire gets blocked by mast for radar.
• Pretty similar to Shivaliks but on paper this should perhaps be the best integrated CIWS we ever had apart from obviously Kashtans. 16x Barak-1 and one AK-630 on each side guided by their own fire control radar, all mounted pretty close to each other. Nice

And from here things take an interesting turn as we move up

10. Kolkata - Vishakapatnam Class
View attachment 19474
• Obviously sub optimal placement; instead of two cluster of two one could easily go with one each on bow-starboard-stern-port, same amount of guns but improved overlapping arcs of fire. Here too, the guns are mounted in such a way the the superstructure interferes not just in front but also in rear. In case of mounting near the hangars (like say Kamorta) only the frontal arc was obscured but here the rear too gets interfered.
• But perhaps most important, there isn't any fire director now. Everything is controlled by the MF-STAR which is perfectly fine except for the band; it's S-band. MF-STAR is used by Koreans and Israelis too but only we use it for CIWS.
No doubt, it can definitely be used for this role but as you move from Ku to S your precision decreases. 2.5 to 3.8cm now becomes 7.5 to 15cm, definitely a difference that you can feel with next gen low RCS missiles like LRASM.

11. Vikrant
Again exactly the same case as P-15s, S-band radar being used for fire control.


As always, everything's just my brainrot shitposting so proceed with caution. Feel free to correct wherever needed. Infact I'm hoping that I'm proven wrong.

Very informative write up

Maximizing flank protection at the cost of frontal protection. Anyway, I think they should see if they can integrate a navalised version of Atulya FCR with the AK-630 mounts.

Having four CIWS and still having blind zones

My personal copium for this is they are leaning into the Italian model of shooting missiles and drones with a 76mm cannon.
Strales/DART ammo combo called in PSU speak as "Upgraded Super Rapid Gun Mount" also fits with this.

Now how useful irl this is for shooting down missiles who knows?

 

[shade2]

If we can get them to expend their 100s of Ks of USD worth SAMs on Shahed type suicide drones worth no more than 15 grands at the most, then I say we've won half the battle already. Heck, one could also use swarms of rocket/ small turbojet powered glide bomb with EO seekers for that, if we are feeling crafty.
All good against anti-ship missiles as their cost and size puts a limit on how many you can realistically throw at any one particular target; not so much against a large swarm of cheap loitering munitions/ long range glide powered glide bombs. Against those, a gun based CIWS with a large magazine size will trash a missile based CIWS every damn time.

Do our current AK-630s have "large magazines"?

imo Oerlikon Millenium gun type 30mm cannons should be enough for USV and Shahed type UAVs that use propellers, basically a gun which has the programmable "shotgun" type blast at a set distance from target.

gatling gun ciws should be reserved for missiles or anything which has a rocket motor

Anyway from what i've read here our CIWS weaknesses are
>Centrally directed AK-630, need per ciws radar and eo pod like phalanx and goalkeeper
>No RAM Launcher type missile/launcher combo and as per ayan barat no existing deshi missile either, for AMRAAM permissions will have to be taken from (((Anglo)))
>AK-630 cannon itself has shot dispersion issues

 

[Ayan Barat]

Very informative write up

Thanks

The RBU 6000 is more of a hardkill anti torpedo measure than a proper ASW.

Yeah...kind off. In current configuration it'd be perhaps the most lousy hardkill anti-torpedo system as you'd need to fire a full salvo of unguided rockets just to intercept one torpedo. You'd need specialists rockets whose payload are tiny torpedos designed to home into incoming torpedo.

But then again, this doesn't justify having RBU-6000. RBU-6000 are extremely deceiving to the eyes because people usually see the launcher and miss the under deck equipment that take up huge space

If we indeed develop TorBuster type ammo for RBU-6000 then there's no need to have an under deck magazine as increased hit probability would inherently increase the magazine depth. We can simply mount just the launcher part throughout the ship like three each on port and starboard.

With the Nilgiri Class receiving the DART/STRALES 76mm guided ammunition as part of the upgraded 76/62 mm SRGM, the main gun can now be used in CIWS roles with the MF-STAR acting as the FCR.

Now how useful irl this is for shooting down missiles who knows?

It's good, maybe excellent given the dire state our CIWS is. First thing it'll do is cover one of the biggest blind zone in the frontal arc. Second, you'd missile like range from a "relatively" cheap ammo.
But again, as with any system this too has compromises. The bore is 76mm and DART is a sub-caliber ammunition so you don't have enough SWaP to mount any kind of fire-n-forget guidance. Instead it's kind of like earlier SACLOS ATGMs where you had to manually guide the round till it impacts.

So instead of firing rounds in quick succession at three approaching targets from different directions it'll engage only the first one and would be "occupied" with it till engagment is done. Then it'll lay to next target.
In comparison, a "dumb" CIWS would rapidly fire a burst at each of those three missile in quick discussion with first on the closest and last on the farthest. And then wait to see which one needs rengagment. And a missile based CIWS would just fire three or six missile simultaneously; either in fire-n-forget mode or guiding all of them individually using data-link.

Do our current AK-630s have "large magazines"?

Overall you've 2,000 rounds and it's upto the target that how many engagment can be done. If say you're being attacked by small loitering munitions then you'd hardly need 10-15rds to down it; so you now have 130-200 available "shots". But for a supersonic anti-ship cruise missile you might need 100-150rds to detonate it with enough stand-off that the shrapnel don't damage sensitive equipment; effective "shots" now come down to just 13-10.
So it's bit tricky to say, but yeah...2,000rd is good considering all the contemporaries.

Moreover as soon as the proximity fuzed ammo comes in service this effective "shot" would increase drastically.
Like now you'd need just 5rds to down a loitering munition type target.

 

[vampyrbladez]

Thanks

Yeah...kind off. In current configuration it'd be perhaps the most lousy hardkill anti-torpedo system as you'd need to fire a full salvo of unguided rockets just to intercept one torpedo. You'd need specialists rockets whose payload are tiny torpedos designed to home into incoming torpedo.

But then again, this doesn't justify having RBU-6000. RBU-6000 are extremely deceiving to the eyes because people usually see the launcher and miss the under deck equipment that take up huge space
View attachment 19514
If we indeed develop TorBuster type ammo for RBU-6000 then there's no need to have an under deck magazine as increased hit probability would inherently increase the magazine depth. We can simply mount just the launcher part throughout the ship like three each on port and starboard.
View attachment 19515


It's good, maybe excellent given the dire state our CIWS is. First thing it'll do is cover one of the biggest blind zone in the frontal arc. Second, you'd missile like range from a "relatively" cheap ammo.
But again, as with any system this too has compromises. The bore is 76mm and DART is a sub-caliber ammunition so you don't have enough SWaP to mount any kind of fire-n-forget guidance. Instead it's kind of like earlier SACLOS ATGMs where you had to manually guide the round till it impacts.
View attachment 19518
So instead of firing rounds in quick succession at three approaching targets from different directions it'll engage only the first one and would be "occupied" with it till engagment is done. Then it'll lay to next target.
In comparison, a "dumb" CIWS would rapidly fire a burst at each of those three missile in quick discussion with first on the closest and last on the farthest. And then wait to see which one needs rengagment. And a missile based CIWS would just fire three or six missile simultaneously; either in fire-n-forget mode or guiding all of them individually using data-link.

Overall you've 2,000 rounds and it's upto the target that how many engagment can be done. If say you're being attacked by small loitering munitions then you'd hardly need 10-15rds to down it; so you now have 130-200 available "shots". But for a supersonic anti-ship cruise missile you might need 100-150rds to detonate it with enough stand-off that the shrapnel don't damage sensitive equipment; effective "shots" now come down to just 13-10.
So it's bit tricky to say, but yeah...2,000rd is good considering all the contemporaries.

Moreover as soon as the proximity fuzed ammo comes in service this effective "shot" would increase drastically.
Like now you'd need just 5rds to down a loitering munition type target.

DRDO has developed Extended Range Anti-Submarine Rocket (ER-ASR) (8.5 Km) munitions for the RBU 6000 but I'm not sure if these rounds are guided.

Still with a 72-96 round capacity per launcher we are looking at 144-192 rounds per capital ship (2 x RBU 6000).

That can also neutralize swarm AUVs which have crippled the Black Sea Fleet pretty economically.

BDL is working on license producing Torbuster but I'm not sure if we are planning to fit them in an RBU 6000.

BDL Aims to Build Next-Gen 'Torbuster' Torpedo Decoys for Indian Navy: BDL Chief

BDL Aims to Build Next-Gen 'Torbuster' Torpedo Decoys for Indian Navy: BDL Chief

In a major move to fortify the Indian Navy's defenses, Bharat Dynamics Limited (BDL) has teamed up with Israeli defense firm Rafael to offer the advanced Torbuster SP hard-kill decoy system. This...

defence.in

 

[Ayan Barat]

DRDO has developed Extended Range Anti-Submarine Rocket (ER-ASR) (8.5 Km) munitions for the RBU 6000 but I'm not sure if these rounds are guided.

Naah...pretty usual vanilla rounds with maybe a two stage rocket engine. Orange, first stage one being the original motor. And the grey one seems to be the new addition.

90R is the original guided version produced in Russia

You can't see the motor and parts of fin of the teeny tiny torpedo that's released from it. This is how it looks

But as the SWaP is limited (diameter by tube bore diameter and length by max length that can be handled by the auto-loader) you run into an interesting issue. You add a anti-torpedo torpedo in it and the available space for rocket motor decreases; so max range is now 4.5km. You added bigger motor to get to 8.5km and now you don't have enough space to add the anti-torpedo torpedo.
So yeah, it's a thing too

BDL Aims to Build Next-Gen 'Torbuster' Torpedo Decoys for Indian Navy: BDL Chief

Per Rafael, it uses its separate launch tubes. These are the dimensions, don't know whether you can modify RBU-6000's system or not. RGB-60 is 212mm in diameter and max length is 1830mm.