Mathematics is a universal subject. If you choose to pursue a . in Mathematics, there will be a lot many options that you will be able to chose from. You can work in different areas such as:

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.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.Hope it helps.