Rectification of mistakes :
Section – 34. (1) With a view to rectifying any mistake apparent from the record—
(a ) the 21[Assessing Officer] may amend any order of assessment or of refund or any other order passed by him;
22[( aa) a gift-tax authority may amend any intimation sent by it under sub-section (1) of section 15 or enhance or reduce the amount of refund granted by it under that sub-section;]
23[( b) the 23a [Joint] Director or 23a[Joint] Commissioner or Director or Commissioner or Deputy Commissioner (Appeals) or Commissioner (Appeals) may amend any order passed by him under section 17A;
(c ) the Deputy Commissioner (Appeals) or Commissioner (Appeals) may amend any order passed by him under section 22 24[* * *];
(d ) the Commissioner may amend any order passed by him under section 24;
(e ) the Appellate Tribunal may amend any order passed by it under section 23 or section 25.]
(2) Subject to the other provisions of this section, the authority concerned—
(a ) may make an amendment under sub-section (1) of its own motion; and
(b ) shall make such amendment for rectifying any such mistake which has been brought to its notice by the assessee, and where the authority concerned is the 25[Deputy Commissioner (Appeals)] 26[or the Commissioner (Appeals)] or the Appellate Tribunal, by the27[Assessing Officer] also.
(3) An amendment, which has the effect of enhancing an assessment or reducing a refund or otherwise increasing the liability of the assessee, shall not be made under this section unless the authority concerned has given notice to the assessee of its intention so to do and has allowed the assessee a reasonable opportunity of being heard.
(4) Where an amendment is made under this section, an order shall be passed in writing by the gift-tax authority concerned.
(5) Subject to the provisions of sub-section (2) of section 28 [33A], where any such amendment has the effect of reducing the assessment, the29[Assessing Officer] shall make any refund which may be due to such assessee.
(6) Where any such amendment has the effect of enhancing the assessment or reducing a refund already made, the 30[Assessing Officer] shall serve on the assessee a notice of demand in the prescribed form specifying the sum payable, and such notice of demand shall be deemed to be issued under section 31 and the provisions of this Act shall apply accordingly.
(7) No amendment under this section shall be made after the expiry of four years 31[from the end of the financial year in which the order sought to be amended was passed].]