Tex. R. Disc. P. 3.03
After the trial judge has been appointed assigned , the Chief Disciplinary Counsel shall promptly file the Disciplinary Petition and a copy of the Supreme Court's appointing Order Presiding Judge's assignment order with the district clerk of the county of alleged venue. The Respondent shall then be served as in civil cases generally with a copy of the Disciplinary Petition and a copy of the Supreme Court's appointing Order Presiding Judge's assignment order . In a Disciplinary Action, venue shall be in the county of Respondent's principal place of practice; or if the Respondent does not maintain a place of practice within the State of Texas, in the county of Respondent's residence; or if the Respondent maintains neither a residence nor a place of practice within the State of Texas, then in the county where the alleged Professional Misconduct occurred, in whole or in part. In all other instances, venue is in Travis County, Texas.
Tex. R. Disc. P. 3.03