Tenn. Code Ann. § 29-20-305: Action in circuit court generally - General sessions court in certain counties

(a) If the claim is denied, a claimant may institute an action in the circuit court against the governmental entity in those circumstances where immunity from suit has been removed as provided for in this chapter; provided, that in counties having a population of more than eight hundred fifty thousand (850,000), according to the 2000 federal census or any subsequent federal census, an action under this section may also be instituted in the general sessions court.

(b) The action must be commenced within twelve (12) months after the cause of action arises.