(1) The Commissioner may, either of his own motion or on application by the assessee for revision, call for the record of a proceeding under this Act which has been taken by the ¹ [Assessing Officer] subordinate to him and may make such enquiry or cause such enquiry to be made and, subject to the provisions of this Act, may pass such order thereon as he thinks fit.
     (2) No order which is prejudicial to the assessee shall be passed under this section unless the assessee has been given an opportunity of being heard.
     (3) No order under this section shall be passed by the Commissioner, if an appeal against the notice of demand issued by the ² [Assessing Officer] under section 20 is pending before the Commissioner (Appeals).
     (4) No order under this section shall be passed after the expiry of two years from the end of the financial year in which the order sought to be reviewed has been passed.
     ³ [(6) On every application by an assessee for revision under this sub-section, made on or after the 1st day of October, 1998, an order shall be passed within one year from the end of the financial year in which such application is made by the assessee for revision.
     Explanation.--In computing the period of limitation for the purposes of this sub-section, the time taken in giving an opportunity to the assessee to be re-heard under the proviso to section 24 and any period during which any proceeding under this section is stayed by an order or injunction of any court shall be excluded.
     (7) Notwithstanding anything contained in sub-section (6), an order in revision under that sub-section may be passed at any time in consequence of or to give effect to any finding or direction contained in an order of the Appellate Tribunal, ⁴ [the National Tax Tribunal,] the High Court or the Supreme Court.]