I congratulate you for having a focussed dream of your career at an early age.
If you want to make your career in this line you will have to pursue Physics and Mathematics and in graduation and postgraduation selecting astrophysics/ astronomy as your specialized subject. Only thing is it may not be available everywhere so you may have to apply in the appropriate college.
Another thing is there are some big research institutes and colleges where astrophysics is a full fledged subject. You have to try there for admission. Some of the top institutions for Physics and Astrophysics/ Astronomy are as follows -
1. Indian Institute of Technology, Bombay
2. Tata Institute of Fundamental Research, Mumbai (TIFR)
3. University of Delhi (DU)
4. Indian Institute of Science, Bangalore (IISc)
5. Indian Institute of Technology, Delhi (IIT-D)
6. Indian Institute of Technology, Madras
7. Indian Institute of Technology, Kharagpur (IIT-K)
8. Banaras Hindu University, Varanasi (BHU)
9. Indian Institute of Astrophysics, Bengaluru
10. Institute of Mathematical Sciences, Chennai (IMC)
One thing whether you have interest in astromy as an hobby if so it will help you in your career.
Once you complete your higher education in astronomy you can apply for research or job even at NASA. There are many Indians working in NASA.
Knowledge is power.