Hii

Optional Subject are those which you have taken as Optional and there marks will not be added in your 12th Result when you apply for admission.

In your case, you can apply for both JEE Mains & NEET Exam, were PCM score & PCB score will be validated respectively.

NEET Eligibility Criteria 2019

https://medicine.careers360.com/articles/neet-eligibility-criteria

JEE Mains Eligibility Criteria 2019

https://engineering.careers360.com/articles/jee-main-eligibility-criteria

All the best.