Dear aspirant,

As per the information given on the official site of University of Delhi, it is clearly stated that the OBC certificate of an applicant must be issued by SDM.

To know more, access the link below. The link contains all the information regarding UG admission is DU.
Microsoft Word - FAQs related to admission against Reserved Category.docx (du.ac.in) (https://www.du.ac.in/du/uploads/COVID-19/01072020_FAQs%20related%20to%20admission%20against%20Reserved%20Category.pdf)
Hope this helps!