Engineering

For IIT-B, the cut-offs in the past few years have been between 1.5K and 2K for aerospace. The same has been ~2.5K-2.7K for IIT-K, and ~3K for IIT-M and IIT-KGP.
Regarding marks, scoring slightly above 50% of the max marks will surely land you with a rank close to 2k, which is sufficient for getting

I would request you to go through this article by Times of India to get a clear understanding.
https://timesofindia.indiatimes.com/home/education/news/MBA-vs-MTech/articleshow/21908011.cms

Basically, the purpose of appearing for the NET exam is to enter into the field of teaching. Also, those interested in the research field need to appear for this exam along with the JRF exam. It has now become mandatory to receive the UGC pay scale the candidate should have cleared the NET exam. Any

kiet is best among NIET gcet and akgc

CSE:
BNMIT (round 2)
RNSIT (round 2)
ISE
BNMIT
RNSIT
Mechanical:
PES, South Campus (top colleges under ComedK)
BIT-Bangalore
MVIT-Bangalore
Electrical
BMSIT
MVIT-Bangalore
The best option according to me is mechanical at PES, South Campus which is a very reputed college.

There are chances that you can get CSE at Reva University.
Let's hope for the best.

In engineering, there's a variety of branch you can select. Pursue only in which you are interested and you can handle it easily.
All the best. Go ahead.

It's better to search in online.

Yes, of course, you can do it.

Kindly contact the college officials or the current students of the college.