You will typically need the original document, a clear colour copy of the holder's passport, and a UAE residence visa or Emirates ID copy where the applicant is UAE-based. Educational documents usually need pre-verification by the issuing university or by HRD in the state of issue before MEA will accept them.
Skipping a required state or HRD step is the most common rejection cause for Indian documents specifically, because MEA cannot verify a document that hasn't first passed through the correct state authentication. Documents issued in a language other than English — some south-Indian state records, for example — may need a certified translation before UAE authorities accept them. Name spelling mismatches between the document and passport halt the file at any stage. And commercial documents need Chamber of Commerce attestation in India first, without which MEA will not process the file.