Hello Dear,

if you want to join IIT Madras then you have to clear the jee-advance exam with a good rank, this is for UG program.

https://engineering.careers360.com/articles/jee-advanced-cutoff-for-iit-madras

if you looking PG courses then you have to qualify GATE exam with a good rank.

https://engineering.careers360.com/articles/gate-cutoff-for-iit-madras

good luck