Admission to IIT Delhi happens through JEE Advanced. For appearing in JEE Advanced, you need to qualify JEE Mains first, i.e. you should be in the top 2.5 lakh students. For getting a seat in CSE in IIT Delhi, you should be one of the top rankers in the exam. The category wise cutoff rank for CSE in 2019 (gender neutral category) was as follows:

• General: 93
• EWS: 12
• OBC: 65
• SC: 39
• ST: 19

Now it is difficult to tell the exact marks as the marks vs rank data varies year to year depending on the level of the question paper and performance of the appearing candidates. Although you should be one of the top performers to grab a seat in CSE in IIT Delhi.

For previous years' cutoff for different branches in IIT Delhi, please visit: https://engineering.careers360.com/articles/jee-advanced-cutoff-for-iit-delhi/amp