Your registered unique college roll no. for the purpose is a 5 digit number which can be obtained by adding a stream no. to your class roll no. Stream numbers are :
10000 for BA
20000 for BSc
30000 for BBA
For example: If a student has class roll no. 108 in BA stream, her registered college roll no. will be (10000+108=)1108.
Update1: Last date of application has been extended upto 10-11-2018.