Hello, 

A score of 103 is a low score to get admission in MBBS even with a reservation category. The cut off marks for MBBS under All India Quota is 450 and above for SC category. The cut off marks for state quota might be 350 and above depending upon the state in which you are applying for MBBS. Looking at the last year's cut off marks for both State and All India Quota, with a score of 103, the chances of admission for MBBS in SC category might be very difficult. 

Good Luck.