I'm an average student I got 88 and 73 in 10th and 12th class Will I get admission in FMS Delhi?

According to the new selection criteria for 2021, you will lose 10 out of 20 marks for your previous academic performance. In the initial selection phase, FMS Delhi does not consider a candidate's academic background; however, 20% of the final selection criteria are based on academic performance. 

Obtaining a 99+ percentile may guarantee a call, but the call will be wasted if you cannot convert it. Even if you performed exceptionally well in the interview, the likelihood of conversion is low. You must compensate for any academic points you may lose by achieving a high CAT score.