Section 56(2)(a) in The Tamil Nadu Town Panchayats, Third Grade Municipalities, Municipalities and Corporations (Elections) Rules, 2006
(a)The Presiding Officer of each polling station, as soon as practicable after the close of the poll, shall close the slit of the ballot box or boxes and where the box does not contain any mechanical device for closing the slit, he shall seal up the slit and also allow any candidate or polling agent present to affix his seal. The ballot box shall, thereafter, be sealed and secured.