Hi student,

Depends on what exactly you are looking for.

Every IIT has very good professors who are the best in India (or may be even in the world) in their own fields.

If you want me to specifically point at some,
analog VLSI - IITM
Devices - IITB
Digital VLSI - IITB/Kgp/D
Microwave/antenna - IITK

If you are thinking about placements, all the older IITs give same opportunities and it is often governed by the market needs of the companies that visit the campuses.

All the best