Dear Vini,
According to Schedule for PG admission issued earlier online registration process was to begin on May 18, 2018; but DU cancelled it by stating, : It is to notify that the previously announced schedule for Post-graduation admissions for academic session 2018-2019 stands cancelled. The revised admission schedule will be notified soon on the University Website."

I would recommend you to go through Schedule for Announcement of Admission Lists for Postgraduate Programmes (2018-2019), though it stands cancelled but it will provide you information about steps associated with admisson process.

More information is available @ DU LLB Counselling 2018.

I hope it helps!