Hello Nitish !

Admission process is conducted in Delhi University in 2 modes :

1. In first category , only students of University of Delhi are eligible for admission on the basis of merit. 50% of the seats will be filled on the basis of merit in B.Sc. (Hons.) Computer Science programme of DU University students.
2. Admissions for the remaining 50% of the seats in M.Sc. Computer Science programme is based on Entrance Test and Interview.

You can check more about the admission process on their official site by following link :

http://cs.du.ac.in/admission/mcs/

Hope it helps !