The original NOC is requested for Business Visa for "verification" only. The original NOC will be returned by the Immigration department, to the PRO. Check with the company that obtained your Business visa; they should have your original NOC.
If they do not have, you may have to request your previous employer (who gave you the NOC) for a duplicate of the NOC. This should be the same as the old NOC(date, ref. No. etc.)
Good luck!