(a) Except as provided by Subsection (b), an action challenging the validity of or arising out of acts taken or proposed to be taken regarding a conversion plan under this chapter must be commenced not later than the 30th day after the date the conversion plan is approved by the commissioner.
(b) An action challenging the validity of or arising out of acts taken or proposed to be taken regarding a conversion plan that contemplates a public offering of debt or equity registered under the federal Securities Act of 1933 (15 U.S.C. § 77a et seq.), or a similar law of a foreign jurisdiction, must be commenced not later than the 60th day after the date the conversion plan is approved by the commissioner.