Engineering

IIT, Kanpur is best as it is the oldest IIT and equipments and facilities are superb including the location.

If you want to go in networking field then IT or if you like coding or languages then go for CSE.

It's your own interest. If you like to play with the screw driver then no other branch is better than mechanical for you and if you like coding then no other branch is better other than CSE.

Specifically, there is no such college which is famous for a particular branch of engineering. But all the IITs would be better, including:
NIT
BITS Pillani
VIT
DTU
Graphic Era
ABES

There are various colleges which are considered as best engineering colleges for civil engineering:
1. IITs: mainly IIT Delhi, IIT Bombay, IIT Kanpur, IIT Kharagpur, IIT Madras and IIT Roorkee.
2. NSIT Delhi
3. DTU
4. VIT
5. SRM.

Yes, there is a provision of lateral entry in which most students either Diploma students or other students from other colleges can join. It is a very normal process for taking admission in 2nd year.

There are various colleges which are considered as best engineering colleges:
1. IITs: mainly IIT Delhi, IIT Bombay, IIT Kanpur, IIT Kharagpur, IIT Madras and IIT Roorkee.
2. IISC Bangalore
3. NITs
4. IIITs

If your aim is teaching, B.Sc and M.Sc would be surely enough for it. But if you want a decent placement and a job, you should definitely consider B.Tech. You can apply for various universities providing B.Tech degrees and then proceed.

You can consider following colleges:
1. Indian institute of technology, Madras
2. Indian institute of technology, Bombay3. Indian institute of technology, Kharagpur4. Indian institute of technology, Delhi5. Indian institute of technology, Kanpur

The best books to prepare for JEE Mains exam are-
Maths- RS Aggarwal
Physics-SL Arora
Chemistry-NCERT and OP Tandon