IIT Delhi takes admission through JEE Advanced.
In order to appear for JEE Advanced you have to qualify for JEE Main exam.
In order to be eligible you should have 75% marks in your boards exam or you should be in top 20 percentile.
For SC/ST it is 65% marks.
You can check the cut off from the given below link
JEE Advanced 2018 Cut off
Good Luck!!
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile