BSc Mathematics don't offers you a job after BSc(in most cases). In order to get a good career in private sectors you need to have MSc.

Now after BSc you can give the different examinations like SSC-CGL, UPSC etc in order to get jobs in civil services as well as different branches like Income Tax Department etc.

Now you can get accounting jobs in some sectors which is very rare but you can have if you have proper knowledge in the field of Business Mathematics / Industrial Mathematics. Also if you can acquire sufficient knowledges in programming you can get programming jobs in walk-in interviews of different companies like TCS etc.

Now you can also Integrated PhD courses which will be advance your career in maths as well as you will get a stipend of around Rs.30,000. After doing Iphd or PhD you can go for Assistant professorship. Some of the eminent institutes for IPhD or PhD in Mathematics:

1. INDIAN STATISTICAL INSTITUTE
2. INDIAN INSTITUTE OF SCIENCE, BANGALORE
3. CHENNAI MATHEMATICAL INSTITUTE
4. TATA INSTITUTE OF FUNDAMENTAL RESEARCH (preferably TIFR-MUMBAI or ICTS)

I hope you got my point. All the very best for your future endeavors!

Hii!
After completing BSC maths you can go for various options of jobs such as apply into defence forces, prepare for government jobs such as upsc, SSC CGL, etc., Prepare for jobs such as professor, subject matter expert, research, scientist, aeronautics, teacher etc.,
You can complete higher degrees such as MSC, PhD etc., And apply for suitable posts in ISRO, DRDO, research scientist, robotics etc.,
Hope this helps.
Good luck!