Hi Aditi...

The cutoff varies from year to year....U need to get an average of 600 & above for joining PG course in AFMC.

Also other things like one needs to take care while they are being interviewed and also make sure that the candidate is physically and mentally fit and fine. 

Kindly go through the below link for the info on medical fitness required.

http://www.afmc.nic.in/PDFfiles/3511815545AFMC%20MBBS%20Information%20Brrochure%20%202018.pdf