(6)Subject to such rules as may be made, any authority under this Act or its successors in office may, on application or otherwise, review any order passed by it to correct any error or mistake apparent from records:Provided that neither an application under this subsection nor the period during which it is pending shall be considered as cause for the delay, if any, in filing any appeal or application for revision Provided further that no such review shall be made if it has the effect of enhancing the tax or penalty or both, or of reducing a refund, unless the dealer or the person who is liable to pay the tax or the penalty or both, or as the case may be, eligible to get refund, is given a reasonable opportunity of being heard.
