Btech CSE studnets rarely get job opportunities for Astrophysics based roles.

Only 2% jobs in Aerospace and defence sector is alloted to CSE or It studnets for roles like Business Intelligence, Data Analytics, Artificial intelligence.

These are majorly with IsRO and DRDO.

As prerequisites, Btech in Aerospace or Aeronautical enginnering is must.

Scope of astrophysics roles sharedbelow.

http://www.indiastudychannel.com/resources/164161-Where-to-study-astrophysics-in-India-Eligibility-and-Job-Opportunities.aspx