Section 83(1)(c) in The Tamil Nadu Town Panchayats, Third Grade Municipalities, Municipalities and Corporations (Elections) Rules, 2006
(c)The envelops containing the marked ballot papers shall then be opened one after another and the votes counted. If the declaration is not found or has not been duly signed or is otherwise substantially defective, that envelop shall not be opened and after making an appropriate endorsement thereon, the Returning Officer shall reject the ballot paper contained therein.