Hello ridhima arora

I hope you are doing good.  I would glad to inform you that for  appearing in neet exam you should have passed 12 th with physics ,chemistry and biology as core subjects . So it would be not possible to fulfill the eligibitly by taking bio as optional , moreover it doesnt make any sense . However, if you take medical and then you take mathematics as optional then you will also eligibile for neet exam . Anyhow , bio must be mandatory

Hope you found this answer helpful. Good luck for your future