Hi,

After passing your class 12th with BiPc, you can appear for NIOS On-demand examination (ODE) in a single subject ie maths in your case.

NIOS is a recognized board if you qualify on demand Mathematics examination from NIOS board you'll be  eligible to appear in Jee main or other entrance examinations.

You can visit www.nios.ac.in (NIOS WebSite) to enroll yourself for the exam.

Hope it helps.

Regards.