Thats true.
When i went for my pilot training we had a South Indian (tamil) instructor who came and started talking in Hindi and spoke very fluently.
Then he noticed all the south indians standing together and he said …oho atey hi groupism…tum log india k her campus me apna group banate ho but yha nhi hoga..u guys have to hangout together with everyone and speak in English or Hindi whatever you are comfortable in.
I was very surprised a guy from Tamil Nadu saying that but then i was young…now i know how we form communities in campuses and societies which suit our culture or language but it shouldnt be encouraged.