B.Sc Physics

For ethical hacking you may opt for bca rather going for bsc physics. For ethical hacking there are certification that you have to grab. Courses like CCNA CCNP etc are done for these international certifications.

Rahul with Physics you can opt for an intresting technical career. You can aspire to join ISRO for example. You can do research in this field after post graduation. You can, if you attain requisite skills, go ahead and start manufacturing measuring meters & instruments of several kinds. You can be a Professor in the college. You can even opt for a career in Forensic science.

Hi Yashwant,
Kindly refer the below mentioned college predictor tool :
https://www.shiksha.com/jee-mains-college-predictor
I hope this information helps. Please feel free to revert.
Wish you luck.

You can apply for IIT-JAM exam.this exam allows you to teach at IIT.

Hi
b.tech, b.sc in computers are the best options to go in for research in computing field as you may pursue msc or m.tech in CS later. Physics will be little diversified option.

Absolutely you can. Check the details at leading institutes like IISC, IISER and IIA.