Can I become a maths teacher after completing B.Ed?

Go for post-graduation in mathematics if you want to be a maths teacher after your B.Ed so as to became eligible for PGT mathematics.

In most of the government schools eligibility criteria for TGT maths is a graduation degree in maths and B.Ed. You are not eligible to become a maths teacher because of your BCA degree. Some private schools may consider you for TGT maths.