To sell your commercial property, you must have the following documents:
Property title deed, Property tax receipts, Occupancy Certificate (OC) / Completion Certificate (CC) , No Objection Certificate (NOC) from bank which ensure that there is no existing loan or mortgage on your commercial property. Make sure all the documents are authentic.
To protect yourself, consider hiring a trusted real estate lawyer. Try to deal directly with verified buyers or through trustworthy agencies.