Has he completed his studies? Is he still registered as a student? If he is still registered, then he's not entitled to sign on.
If he has finished his course/degree/exams, then he can make a claim for Jobseeker's Allowance at the nearest SW office.
If he's under 25, he will be assessed on his parents income.
There is a backlog on processing claims at the moment, I've just read a post here from someone waiting 11 weeks so far, so payment (if entitled) will take time.
He could make a claim for SWA at the local Health Centre while waiting for Jobseeker's - it will be means tested as well, so he'll have to produce evidence of parents income to the CWO as well as the SW office.