Tenn. Code Ann. § 13-7-113: "Regional planning commission" defined

For the purposes of this part, "regional planning commission" means any regional planning commission established by the [former] state planning office as authorized by law, and includes any municipal planning commission designated by the state planning office, as authorized by law, as the regional planning commission of a planning region composed of the territory of a single municipality, together with territory adjoining but outside of such municipality.