Considering MBBS’s duration of 5 and a half years (including 1 year of compulsory internship), a medical student starts PG (MD/MS/DNB) only by a minimum age of 23 years, provided he/she got into MBBS immediately after school(12th std) not wasting a year.
And given the tremendous amount of competition(backlog + horribly less no of PG seats) these days, a medical graduate after MBBS usually has to drop a year to prepare well enough to crack the PG entrance examination and get into a desired field in a good institution.
So on an average, usually at the age of 24–25, a medical graduate gets into PG. 3 more years of hardship before he/she is qualified enough to treat patients without supervision.