Hi Jaswanth
I would suggest the most basic thing that is first try to analyze about yourself that what are areas you are good at and in which areas you have Interest. Once you find your area of interest then try to find the courses from B Tech which can help you in your career.
If you like computers then go for Cse or IT,  and if you like machines and their working then opt for mechanical, similarly the rest of them.
Once you decide then find the best colleges and the ways to get into those colleges. Do remember before selecting the college check with placements, faculty and opportunities related to that course.
I hope it might help you a bit.
All the best.

Try to Choose those branches where you think that you could do well. Means that if you think that you good in Maths then consider choosing mathematics and computing,if you are good in physics then consider choosing engg. physics this is the one way that you can decide which branch to take.Literally everyone knows where there interest lies so choose accordingly....

--Shubham goel (DTU)