Techno India University

Mathematician - You can choose to pursue research (become a scientist) in your area of interest in maths and if you choose research, you can go into the teaching sector also. Check out institutes like TIFR-Mumbai, IMSc-Chennai, Harish Chandra Research Institute-Allahabad.
Chartered Accountancy - If you like auditing, taxes and accounting, you can think of preparing for CA too.
Banking - Banking is another sector that you can get into with mathematics.
Actuarial Sciences - If you love data and maths, actuarial sciences would be a great field for it.
Data Analysis/Operations Analysis/Project Development - If you want to work in the private sector, you can look at these profiles.
Military Operations - Mathematics degree would also allow you to work in the military sector, scientists are always required to work with military and development (DRDO, ISRO, NAL, SETS, etc.). You can also join the navy as a Commissioned Officer in their education or logistics branch.
Market Researcher - There are a lot of companies that you can work with to identify market patterns and trends, and help in analyzing these trends.