Hi

Neet eligibility  criteria says that,

to be eligible  you must have passed your 12th with English and PCB (in both the theory and practical)  with at least 50 % in aggregate of PCB ( in theory +practical) in 12th examination  if you belong to general category , or  at least  45% in aggregate of PCB if belongs to ph category or at least 40% in aggregate of PCB if belongs to Obc/ Sc /st

So , yes after passing the subjects in which you have failed and getting 50% in PCB to meet aforesaid criteria,  you will be definitely eligible for Neet 2021 examination.

Thank you