Tenn. Code Ann. § 65-3-205

The commissioner of transportation is empowered to employ such rate experts, engineers, attorneys, accountants, auditors, inspectors, examiners, clerks, agents or other employees, and assign to them such duties as shall be necessary to enable the department of transportation to fully perform the duties, and to exercise the powers conferred by this chapter upon the department of transportation, subject to its review. This section shall not be construed to authorize or to permit such attorneys to file any action or to otherwise appear before any state or federal court without prior approval of the attorney general and reporter.