no worries if the online portal are not acctivated yet you can directly visit the college in which you get the admission and submit your fees there easily without any issue. all the best have a great future ahead.

Dear Siddharth,
According to information given in revised Admission Schedule for LLB/LLM one has to pay Fee online using Postgraduate Admission Portal but before that one has to go for the Document Verification process and gain approval of admission.

http://www.du.ac.in/pginterview/LLB_LLM_Schedule.pdf

I hope it helps!