Can I go for game designing after doing the B.Sc in maths?

Well that shall be very different from what skills you have furnished at your graduation. Go for analaytics and Quant Roles in Banks and Financial Institutions.

Yes. You surely can. You simply need to have a passing grade of 60 percent overall in your 12th grade education. So, you are eligible. In addition to that, you had studied mathematics, which will be of great use to you.

Though you can apply for game designing courses after 12th from any stream, skills and knowledge acquired in Science stream is very helpful. Basic knowledge of mathematics and Physics are also a part of the Diploma in Game Design and Development syllabus.