Class 12-science

He can do B.Tech in astrophysics.
List of astrophysics colleges in India:
Indian Institute of Astrophysics, Bangalore
Gulbarga University , Gulbarga
Karnataka City College, Bangalore
R. V. Center for Cognitive Technologies Bangalore
St. Xavier's College, Kolkata
Indian Institute of Astrophysics, Bangalore
Rashtrasant Tukdoji Maharaj Nagpur University, Nagpur
Saha Institute of Nuclear Physics - Kolkata, West Bengal
Institute Of Physics - Bhubaneswar, Orissa
Punjab University - Chandigarh, Punjab
College of Science & Technology - Visakhapatnam, Andhra Pradesh
Berhampur University - Berhampur, Orissa
Kamla Nehru Institute of Physical and Social Sciences - Sultanpur, Uttar pradesh
Source:
http://entrance-exam.net/forum/general-discussion/list-colleges-india-offering-b-tech-astrophysics-524337.html#ixzz4fRERNnCX

Hi Saurav,
You are studying, both Maths and Science, so first you should decide which stream you want to study. If you are interested in Maths, then you can have opportunities in the field of engineering. You can do so by applying in various exams that are being conducted, for example JEE-Mains conducted by CBSE, BITSAT conducted by BITS Pilani and many more. You can also become a researcher by qualifying exams conducted by NISER, IISER. Architecture is also an option that you can avail for. If you choose biology as a stream you can apply for AIPMT for being a doctor, you can also do a UG course in forensic Science, you can give exams like AGRICET, CCS for pursuing career in agriculture. If you want to take bio technology as an option, you can take exam conducted by AIIMS for biotech, AIB (amity institute of bio technology) and many more options are available, so choose it wisely.