Computer Science and Engineering programme at Indian Institute of Madras is one of the most highly regarded and sought after program in the Indian engineering education landscape. If we see the cut-offs of previous years for GEN-PwD candidate, in 2021 it was as follows:

Opening Rank: 2
Closing Rank: 6

So, in order to get these ranks, you'll have to solve around 40 to 45% of the paper correctly and you'll be there without any problems. All the best!