Texas Civil Practice and Remedies Code - CIV PRAC & REM § 101.102. Commencement of Suit

(a) A suit under this chapter shall be brought in state court in the county in which the cause of action or a part of the cause of action arises.

(b) The pleadings of the suit must name as defendant the governmental unit against which liability is to be established.

(c) In a suit against the state, citation must be served on the secretary of state. In other suits, citation must be served as in other civil cases unless no method of service is provided by law, in which case service may be on the administrative head of the governmental unit being sued. If the administrative head of the governmental unit is not available, the court in which the suit is pending may authorize service in any manner that affords the governmental unit a fair opportunity to answer and defend the suit.