Texas Government Code - GOV'T § 554.007. Where Suit Brought

(a) A public employee of a state governmental entity may sue under this chapter in a district court of the county in which the cause of action arises or in a district court of Travis County.

(b) A public employee of a local governmental entity may sue under this chapter in a district court of the county in which the cause of action arises or in a district court of any county in the same geographic area that has established with the county in which the cause of action arises a council of governments or other regional commission under Chapter 391, Local Government Code.