First of all, there is no fixed GATE score that makes you eligible to do a Ph.D. at IIT Madras as the selection process comprises a number is criteria with the GATE score being just one of them. The students applying for a PhD program at IIT Madras, go through a rigorous admission process. To become eligible one needs to fulfill the following criteria
I hope I made it clear!
Admission to a Ph.D. program at IIT Madras depends on a number of factors. The GATE cutoff doesn’t have much weightage in the selection process. For shortlisting, IIT Madras considers the 10th, 12th, graduation, and masters percentile along with your GATE percentile. You need to have a valid GATE score but the required score is lower compared to the M.Tech cutoff.
For selection, more emphasis is placed on your performance in the written test and interview.