To be qualified and to apply for the UPSC Combined Medical Service examination the candidate must have passed with at least 50% marks in Bachelor of Medicine Or MISS, BHMS, BDS etc..

the age of Candidates writting the UPSC Combined Medical Service examination must be above 21 years and below 32 years.

so, after completing your bachelor degree you have to appear for UPSC Combined medical service examination.

To get complete information about UPSC CMS examination you can check in the link given below

https://competition.careers360.com/exams/upsc-cms

hope this information will help you