Hey Pankaj, 

Delhi University is very strict when it comes to document verification. For admission through CW reservation, you need the CW quota certificate, service book and other documents. There is no separate cutoff/merit list for this category and only 5% seats are reserved, so, the officials are going extra strict with document verification.

So, i suggest you to apply for a new certificate or email the DU admission helpdesk asking the query if submitting xerox would work. 

Hope it helps, good luck for admissions!