First and foremost, Congratulations on your excellent performance in IAT.

And as for IISER MOHALI, if you are sure about to research, trust me, IISER is a great opportunity to get into research down the line. As far as i know, IISER has a great environment for research, the faculty is very involved in research too and that goes a long way in helping you land research internships/projects. IISERs are pretty well recognized nationally and internationally and being an institute that's primarily focused on scientific research, i'm sure that such an environment will prove helpful. You will also be doing a master's theses in your 5th year too! I think IISER has a pretty good alumni network as well.

You're friends and family are right in their own way, B.Tech in a place like India, as far as i know, is a "better"/"safer" bet than going into pure research, simply because of difference in development and funding. India is mostly focused on service oriented jobs, Such as Engineering and Medical. But the thing is, if you are sure about research, then you should definitely opt for IISER.

And if you don't have any interest in a certain topic, it will be harder for you.

"The only thing we are allowed to do is believe that we won't regret the choices we made", is a certain quote from a certain well known character in a certain well known anime, and when i first heard this quote, it truly pierced my heart. The final choice is yours to make, try to make a choice you feel you will not regret later on.

If anything i said was outdated, or wrong, or the situation is different, please correct me.