Tenn. Code § 13-3-303
A regional planning commission may adopt the regional plan as a whole by a single resolution, or, as the work of making the plan progresses, may from time to time adopt a part or parts thereof. The commission may from time to time amend, extend or add to the plan or carry any part of the plan into greater detail. Prior to the adoption of the plan or any part, amendment or addition to the plan, the commission shall hold a public hearing thereon, the time and place of which shall be published in a newspaper of general circulation in the county at least thirty (30) days prior to the meeting in which the adoption is to be first considered. The adoption of the plan or any part, amendment or addition shall be by resolution carried by the affirmative votes of not less than a majority of the membership of the commission. The resolution shall refer to the maps and descriptive matter intended by the commission to form the whole or part of the plan, and the action taken shall be recorded on the map or maps and descriptive matter by the identifying signature of the secretary of the commission.
T.C.A. § 13-3-303