No one can tell the exact marks as AIIMS does not reveal the actual score of any person. It only releases a percentile. However, there are certain criteria for marks to get you in AIIMS Delhi.
A score of 145-150 is considered safe for admission to AIIMS New Delhi, whereas a score of 155-160 is considered the safest. With this score, your admission is guaranteed.
However, it is not easy because as competition is increasing day by day, only your hard work and dedication can get you in.