First thing first I don't know from where you got this NLAW thing or who are these guys completely mesmerized by NLAWs but NLAW is definitely not for that sector. Weapons are never a do-all thing, they're designed for just one specific purpose and as you change roles, it's effectiveness starts to deviate. Submarines are excellent for second strike but try using one for air defence.
NLAW is not an "ATGM", was never meant to be one. NLAW is more like an improved RPG.
• Javelin is 22.5kg, ranged 4km and cost $600k per shot...proper ATGM
• LAW-80 was 9kg, ranged 0.5km and used to be $3.5 per shot (98)...unguided disposable rocket
• NLAW is 12.5kg, ranged 0.8km and cost $27k for one shot...see, how it's closer to an unguided rocket than an ATGM
The scenario where it's supposed to be used are forests of Europe or dense cities where the maximum LOS is around 1km, in Himalayas the LOS can go tens of kilometres...if you use an NLAW here then you'd just give a good laugh to PLA soldiers. Himalayas is where even long ranged ATGMs like Javelins start to suffer and you truly feel the need for NLOS weapons.
To get a rough idea about things you need in that sector and in what numbers we can look at PLA because sadly they seem to be tad bit more serious about a possible engagement than us.
• HJ-10, 10km
• HJ-16, 5km
• HJ-12, 4km
Compared to our
• Nag, 4km range
• Konkurs-M, 4km
• MP-ATGM, 2.5km
Even more important is the number of ATGMs expected in one Chinese CAB and one Indian IBG. There's no accurate way of guessing the exact numbers but based on things like the fact that Nag is carried only by NAMICA where as atleast four different platforms have sported HJ-10 so far and what we currently see in our BMP + dismount ORBAT, it's safe to assume they'd be bringing in lot more ATGMs with a good chunk of them being longer ranged. And all this is ignoring the fact that they have a significant headstart in terms of Anti-Tank drones which are both longer ranged and also more numerous.
As for what against PLA armour, I had this long discussion with Binayak Sir once...you can go through it for all the pros and cons of that one specific idea
The scenario is countering Chinese tanks in high altitude battlefields.
Convince me how a single Zorawar LT is better than having four Mahindra ALSV, each armed with 16 long range ATGMs.