Hello,

It completely depends on what your aspirations are. What do you want to do with your degree is the most important factor in deciding your institute. IIT-KGP is one of the best Technical Institutes of India and IISER Pune is simply the best Research Institute of India along with IISER Kolkata. If you are more inclined to completely immerse in the field of chemistry and do everything in the field of chemistry, IISER is the best option, while IIT KGP is a very old institute with a lot of societies and clubs which you can never dream of in IISER. Being a technical institute, you have the exposure with the industries and also provides a lot of options from other departments which are absent in IISERs. 

But IISER curriculum is very research oriented and you might even be encouraged to go for internships from first summer vacation only. You get the required academic exposure with constant seminars and workshops from one's department. Also, you should not think about placements if you are taking this course. I have tried to tell you the best things from both of the institutes and its up to you to choose one of them according to what you want with your life. So, choose wisely and All The Best.

Thank You

Thank You