Hi Aadi

Neet 2021 eligibility  criteria says that, to be eligible  you must  should have passed 12th board examination with physics, chemistry ,biology and English  as core subjects and must have got at least  50  % in aggregate of PCB  i.e Physics, Chemistry and Biology ( in theory +practical) in 12th examination  if belongs to general category , or   at least  40%  in aggregate of PCB if belongs to  Obc/ Sc /st category.

Also, the students with  Biology as an additional/optional subject are eligible for Neet examination.

But ,
it is unsure that you will be eligible by just passing your Biology later on after 12th because as per eligibility criteria students who have passed their 12th board examination with biology as additional subject are eligible and additional subject is nothing but the 6th subject in your board examination.

So,
if you want to be eligible for Neet ,   I will suggest you to give NIOS on demand examination for 12th  with all the  5 subjects including physics ,chemistry biology and English and for the 5th subject you can choose any subject of your choice like Hindi ,Sanskrit, maths or any other subject and after passing,  if you fulfill the aforesaid percentage requirement in PCB  then you will be eligible and can get admission in MBBS on the basis of marks obtained by you in the Neet examination .

And if you appear this year for NIOS on demand examination then you will have to choose the code 1 if your result is awaited at the time of filling the neet application form , as code 1 is for candidates appearing for 12th  examination  2021 or have appeared with subjects including  physics chemistry biology and English but the result is awaited.

If by the time of filling the neet application form, you get your results with required %  to be eligible i. e. at least 50 % in PCB if you belong to general category or at least 40% in PCB if you belong to OBC, SC or St category then you need to choose the code 2 as it is for those who have already passed their class 12th board examination and meet Neet eligibility criteria.

For detailed information about neet examination eligibility go through our page for which link is provided below; -

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

Thank you