If your injury results from the potential liability of a State of Texas agency or its employees, your case is a complicated one and does not conform to many of the timelines and amounts you can sue for when compared to a standard lawsuit.
You need to file a formal claim with the governmental agency you believe is responsible for the injury, and it must be filed within six months of the incident that caused the injury.
Such claims fall under Tex. Civ. Prac. & Rem. Code section 101.101.