Here is previous year marks vs percentile:

According to MH-CET 2018 results, a score between 165 (Highest) - 149 is equivalent to 99.99 percentile, a score of 136 is equivalent to 99.88 percentile and a score of 113 is equivalent to 98.07 percentile.

According to MH-CET 2017 results, a score between 145 (Highest) - 136 is equivalent to 99.99 percentile, a score of 122 is equivalent to 99.87 percentile and a score of 101 is equivalent to 98.1 percentile.