Tenn. Code Ann. § 6-54-403

Any municipality in a county having a population of not less than two hundred thousand (200,000), according to the federal census of 1960 or any subsequent federal census, may by ordinance create and establish a regulatory board for the review and classification of commercial motion picture films, which board shall have the powers herein set forth. The number of members of such board and their terms of office shall be set forth in such ordinance.