Astronomy

Indian Institute of Space and Technology is the best college.

You want to do a core job or what? Yes, these jobs do need science students but remember that there are material management experts and commerce expert jobs too in these fields. Your question is not clear, but I think that you should do a job in that field to suffice your heart's desire.

Admission to the PG courses will be done on the basis of GATE/JEST/UGC NET.

For space science, please complete M.Sc in physics and PhD also. After that, you can apply for entrance exam of ISRO.