Hey dhannanjay.

First of all u must be having a knowledge and good hold on the topic physics for ur higherstudies in the nano region of the particle. Then u must be doing or choosing ur careeer in the PHYSICS discipline in the IITS for ur further studies. See IITS and other good colleges except research based institutions in INDIA offer education based on the engineering base. Thats why IIITS are not as such a good option for doing this.

On my opinion u should be choosing some research based institutions for ur higher studies in the field of quantum or nuclear such as : 

IISc BANGALORE

BHABHA ATOMIC RESEARCH CENTRE 

and other coleges for ur great resesrach and further deep studies to get a grip and mastering in those fields.

Hope this helped u. Ask if u r having any query.

Good Luck.