What are the best IITs,NITs,GFTIs or other private college for B.Tech. CSE in terms of placements,environment and research purposes?

Hello Dhruv
As far IITs are concerned, IIT BOMBAY, IIT DELHI, IIT MADRAS, IIT ROORKEE and IIT KHARAGPUR are considered to be the top IITs.
For NITs, NIT TRICHY and NIT WARANGAL are the top choice of students.
For GFTIs, there are many in this list such as DTU, NSUT, JADHAVPUR UNIVERSITY, HBTU and many more.
Since the ranking keeps on changing every year, there is a slight increase or decrease in their rankings.
I hope it answered your query.