Hi Ankit

Space science offers opportunities that extend beyond pure scientific fields. It deals with the study of universe.there are opportunities for many different types of engineers in different fields of space science including:

Astronomy

Galactic Science

Stellar Science

Space colonization and space defense

GIS

ATMOSPHERIC SCIENCES

Different types of engineers include:

Aerospace and Aeronautical engineers

Avionics and instrumentation engineer

Computer engineer

Robotics engineer

Telecommunication engineer

Coming back to your query

You must develop an Aptitude Towards Physics and Mathematics. A space Scientist must have PCM as core subjects and have secured excellent score in board exams.

Most of the Reputed colleges conduct entrance exams like IIST, JEE, AIEEE and BITSAT.  Also you can take up M.sc program from IISER ( Indian institute of Science Education and Research). This is a 5 year course which will also help to build up a career as Space Scientist. 

Some universities and institutes for space Scientist are:

1. Indian Institute of Space Science and Technology, Situated in Thiruvananthapuram, Kerala Is Managed by ISRO.

2. Institutes that Offer Post-graduate and Doctoral courses in Space Science Related courses like Astro-physics and Astronomy Are IISC and IIAP, both situated in Bangalore.

3. Institutes that offer courses for astronomy: 

BAMU University, Aurangabad

Madras University, Chennai

Birla planetarium, Kolkata

Rama Research Institute, Bangalore

Inter University For Astronomy And Astrophysics, Pune

National Center For Radio Astronomy, Pune

If it sounds like the Space Science Field is the Right one for you, it's important to Investigate the different types of Jobs that appeal you.

All the Best!!