Hi

You don't need to worry at all the dear even if you are doing your class 12th with PCM from CBSE board and now you want to do your 10+2 again from state board with PCB.

Neet eligibility  criteria says that, to be eligible  you must have passed in English and in both the theory and practical  of PCB i.e Physics, Chemistry and Biology individually with at least  50  % in aggregate of PCB ( in theory +practical) in 12th examination  if belong to general category , or   at least  40%  in aggregate of PCB if belongs to  Obc/ Sc /st

So, if you do again your 11th and 12th with PCB from state board and fulfill the above mentioned percentage criteria in PCB then you will be definitely eligible for Neet examination with your qualification and don't worry you won't face any problem during admission regarding document verification or anything else due to this, if you managed to qualify Neet examination

Also,
Minimum age limit is 17 years old ,so  to be eligible for neet 2021 one has to be at least 17 years old by  31st  December 2021

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

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

Thank you