Hello Aspirant.

Your question probably has the longest answer because this is a very vast and rapidly growing field so the branches or the variations offered in the B.Tech. field are quite great in number. For your help and convenience I am mentioning a handful of them below:

1. B.Tech. with computer science/IT
2. Mechanical Engineering
3. Marine Engineering
4. Electrical and Electronics Engineering
5. Aeronautical Engineering
6. Civil Engineering
7. Aircraft Maintenance Engineering
8. Chemical Engineering
9. Biotechnology Engineering
10. Automation and Robotics Engineering
11. Electronics and Communication Engineering
12. Ceramic Engineering
13. Aerospace Engineering
14. Mechatronics Engineering
15. Metallurgical Engineering

These are some of the well known, unique and high scope branches of engineering.

All the best for your future aspirations and I hope my answer must have cleared your doubt.