Have to cancel my addmission but college not returning my documents

Dear Client, as per your query, Colleges cannot hold onto the original documents (mark sheets, certificates) after admission cancellation, even if there are fee dues, as per UGC guidelines. A formal written request to the Principal, complaint to the UGC e-Samadhaan portal, and sending a legal notice are the next steps if they do not comply.  I hope this answer is helpful. In case of further queries, please do not hesitate to contact us. 
Thank You.