Maths Spl

You probably can. As eligibility criteria is decided by the university itself and it can be different for different colleges. So, check with the college for this.

Mathematics has some scope in government sector mostly. There are several options for a Maths Graduate like Teacher or Professor after giving NET exam. Junior researcher in various Indian research institutes like DRDO, ISRO, BARC etc.

Yes, why not. You are eligible for MCA. The requirement for doing MCA is you have done BCA before.

You can pursue B.Sc. Maths from IGNOU. Visit IGNOUs official website and find your local study center.

These are do or die chapters in mathematics. Limits, continuity & differentiability. Application of derivatives. Definite integration.
3-D geometry. Sequence & Series. Probability. Straight lines. Circles. Matrices. Complex numbers.

Don't stress out too much. Choose what you are comfortable with. Select a subject that you like and are interested in. If you are asking for opinion then I would suggest choosing social studies because it contains history and that doesn't change with syllabus.

There is no such ranking of a department of a college but this college is one of the top 5 science colleges of DU.
The only disadvantage of this college is that it is an off-campus college.

Financial studies don't require maths in 12th. It is not compulsory. You can pursue BBA, MBA and PGDM without taking maths in 12th.

Yes, you can give ICAR without a doubt. But you have to clear the maths compartment to get your result. You can not be failed or have back log in any subject before at the time of admission in a college. Try to clear it as soon as possible and in 1 attempt because then you may have to wait another year to do so.