Tennessee Code Title 4. State Government § 4-21-1004

(a) To protect the free flow of information from citizens to their government, an agency receiving a complaint or information under § 4-21-1003 may intervene and defend against a suit precipitated by the communication to the agency.  If a local government agency does not intervene in and defend against a suit arising from a communication protected under this part, then the office of the attorney general and reporter may intervene in and defend against the suit.

(b) An agency prevailing upon the defense of immunity provided for in § 4-21-1003 is entitled to recover costs and reasonable attorneys' fees incurred in establishing the defense.  If the agency fails to establish such defense, then the party bringing the action is entitled to recover from the agency costs and reasonable attorneys' fees incurred in proving the defense inapplicable or invalid.