Economics

MBA because you once you clear CAT, MAT, entrance with high percentile you can get into IIMs, which would give you more Salary packages. You will be get many many more things. And you will come out in flying colours. But, the only thing is you must buckle down in your studies, so work hard and do your best and win it.

Hi,
There are 100 colleges in India offering these two courses, so you may check here:
https://www.shiksha.com/bba/articles/top-10-bba-colleges-in-india-blogId-7797
https://www.shiksha.com/bba/colleges/bba-colleges-india#coachMark

Public Administration is the best subject for IAS because where you learn that to do well in future, help in interview,small syllabus, GS support & better from previous performs.

You are eligible to pursue BA (Hons.) economics provided you have maths or business maths as a subject in 10+2 board.

You may refer list of top colleges for doing BA Hons Economics or BBA in India:
BA Hons Economics:
https://www.shiksha.com/humanities-social-sciences/ranking/top-arts-colleges-in-india/95-2-0-0-0
BBA: https://www.shiksha.com/bba/ranking/top-bba-colleges-in-india/93-2-0-0-0

TISS does not offer MA Economics degree. You may refer to following link for list of MA courses offered by TISS:
https://www.tiss.edu/academics/teaching-programmes/

Mathematics has more scope than economics.