B.Tech

You are eligible for sure but you have to clear JEE Mains and then, you have to clear JEE advanced to get a seat in IIT.

Text book for physics:
1 HC Verma
2. NCERT
3. Irodov
Text book for chemistry
1. N Avasthi ( Physical )
2. MS Chouhan and NCERT ( Organic )
3. NCERT (Inorganic )
Text book for maths
1. Arihant Series Books
And offcourse the most important:
* Previous years JEE Mains and JEE Advanced question bank.

Amity University, SRM University and BITS Pilani are some of the best colleges.

Yes, there are always some scholarship scheme in private colleges for brighter and poor students.
You may get scholarship for your board percentage. Kindly contact your college once about this.

Yes, you can easily get admission there through your rank. Your rank is more than enough of what is required for taking admission there.
Good luck.

Yes, I think you can get admission into this college because Netaji Engineering Colleges ranked after Techno India in West Bengal.
Best of luck.

There are many good colleges in Jaipur where you can get the admission. You have to decide which college is good for your overall development. You can visit a few colleges in Jaipur like LMNIT and Anand -ICE.

Biotechnology has lot of scope in today or in future, it is best time to do because of lot of problems faced by citizens, industry are health and environment.

You can do distance, open engineering from ignou, Sikkim-manipal University etc, can also apply to institution of engineers which is equivalent to engineering.