CA

CA+CS is a professional career & personally, I would rate it higher than MBA+CS. Since, you have mentioned that you are interested in Law as well then a CA qualification would be of a lot of help to you for specialising in legal matters related to financial domain.
Even if you are not able to clear CA, a CS & LLB will also give you a professional career as a company secretary/consultant in a law/advisory firms.

You require maths for that.

Both of them are linked to each other, because the course you study in B.Com is same in CA. The concept is same in CA as B.Com with a very deep knowledge and some practical approach.

Hello,
Thanks for asking.
There are various options are available for B.Com graduates.
If you want to go for further studies, then pursue M.Com or MBA.
But if you want to get a job, then you can also prepare for government job exams like SSC CGL, UPSC exams, banking exams, etc.
Government job preparation is really good option for secure job & future.
You can prepare & appear in more than one exam at the same time.
Check :
Bank exam preparation : https://www.eduncle.com/ibps-rrb-recruitment-exam
UPSC exam preparation : http://mrunal.org/upsc
Best of luck.

NEET, EAMCET, ICAR, JEE and some university exams.