You are definitely eligible for both JAM (Joint Admission Test for Masters) and GATE (Graduate Aptitude Test in Engineering) with a BSc CS degree. Both exams are popular pathways for pursuing an MSc in Computer Science in India.

JAM focuses more on theoretical foundations of computer science, while GATE emphasizes application-oriented computer science concepts relevant to various engineering fields.
JAM scores are generally used for admission to pure MSc CS programs, while GATE scores are used for admission to M.Tech (Master of Technology) programs with a specialization in Computer Science or related fields.

If you prefer a more theoretical foundation in CS and aim for a research-oriented MSc program, consider taking JAM.

If you are interested in a specialization within CS with an engineering focus and aim for a more application-oriented M.Tech program, consider taking GATE.

https://engineering.careers360.com/exams/gate

I hope it helps!