The eligiblity criteria for NEET PG 2021 says that you should have completed your mandatory internship atleast by March 31st of 2021. If you start your internship on Maay 8th, 2020 you are likely to complete it by May 7th, 2021 rendering you ineligible. But due to Corona pandemic things and schedules have gone haywire. If that is considered, the authorities might look into the dates. This is no certain information and just is purely speculative.