Rectification period shortened for Appellate Tribunal to a limited post-order window; cross-reference to related subsection removed consequentially. Amendment limits the Appellate Tribunal's power to rectify any mistake apparent from the record by replacing the earlier four year window with a short statutory period measured from the end of the month in which the order was passed, and omits a cross reference to a now deleted related subsection as a consequential change, effective from the stated commencement date.