(a) Except as provided by Subsection (b), a person may not practice law in this state unless the person is a member of the state bar.
(b) The supreme court may promulgate rules prescribing the procedure for limited practice of law by:
(1) attorneys licensed in another jurisdiction;
(2) bona fide law students; and
(3) unlicensed graduate students who are attending or have attended a law school approved by the supreme court.