Among AIIMS and PGIMER, the latter is comparably better. The experience and exposure you will get there are unmatched. 

AIIMS has a tendency to refer simple or non-interesting cases to Safdarjung, so students don’t get the chance to see all types of cases. PGI on the other hand is not a referral medical center. So, residents can see all types of cases from simple to complicated. 

Although owing to its location, AIIMS offers better training platforms for residents to take off.