Science

You will be asked everything from your 11-12th, so revise your basics and practice thoroughly.

Follow the below mentioned link:
https://www.shiksha.com/science/colleges/distance-correspondence-m-sc-colleges-india

The minimum eligibility is 50% in UG and I see that you have 92% which is more than enough for you to get admission.

If you want to become a space scientist then you have to have a Ph.D. in astronomy or astrophysics. At undergraduate level, you have to study pure physics and then in Masters you can take astronomy, cosmology or astrophysics, etc. Most of the work related to space science is carried out at Physics R

Yes, you are eligible for this subject, you can apply for the admission.

According to my knowledge, B.Sc. Cardiology has good scope in terms of salary. You should take admission in B.Sc. Cardiology.

Your rank is good enough to get admission here with a free seat. You can apply for admission.

Yes, you do B.Tech in agriculture without studying maths in class 12th.

Eligibility Criteria required for admission :
Minimum 50% requierd in class 12th with Mandatory Subjects : English, Mathematics
Candidate must have passed mandatory subjects with Computer Science / Informatics Practice / Computer Applications / Multimedia & Web Technology / Data Management Application