You might either select for RF & Microwave at IIT KGP and opt for sliding, incase you think you have better options like VLSI at some of the Top 8 IITs. Honestly speaking, RF & Microwave students have lower prospects when it comes to placements. You do have options still, but most of the Electronics Companies open for VLSI & Embedded Systems Stream. You still have options with Software, Analytics, Data Science, Edtech Firms and Startups, but youll have a very effective and interesting college life at KGP with its diverse culture and excellent faculty and research facilities. Incase youre planning Government Jobs, PSUs or joining Public Research Organizations like DRDO, ISRO, BARC, CSIR where effectively RF & Microwave Technology comes in real use, IIT KGP is the best place. Even if youre planning a PhD in future, this is the place for you.