(2)The Appellate Tribunal may, at any time within four years from the date of the order, with a view to rectifying any mistake apparent from the record, amend any order passed by it under sub-section (1), and shall make such amendment if the mistake is brought to its notice by the assessee or the [Assessing Officer] [ Substituted by Act 4 of 1988, Section 2, for " Income-tax Officer" (w.e.f. 1.4.1988).]:Provided that 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 sub-section unless the Appellate Tribunal has given notice to the assessee of its intention to do so and has allowed the assessee a reasonable opportunity of being heard:[Provided further that any application filed by the assessee in this sub-section on or after the 1st day of October, 1998, shall be accompanied by a fee of fifty rupees.] [ Inserted by Act 21 of 1998, Section 53 (w.e.f. 1.10.1998).][(2-A) In every appeal, the Appellate Tribunal, where it is possible, may hear and decide such appeal within a period of four years from the end of the financial year in which such appeal is filed under sub-section (1) ] [ Inserted by Act 27 of 1999, Section 86 (w.e.f. 1.6.1999).][or sub-section (2)]] [ Inserted by Act 10 of 2000, Section 68 (w.e.f. 1.6.2000).][of section 253:] [ Inserted by Act 27 of 1999, Section 86 (w.e.f. 1.6.1999).][Substituted by Act 21 of 1998, Section 52, for sub-Section (6) (w.e.f. 1.10.1998).][Provided that the Appellate Tribunal may, after considering the merits of the application made by the assessee, pass an order of stay in any proceedings relating to an appeal filed under sub-section (1) of section 253, for a period not exceeding one hundred and eighty days from the date of such order and the Appellate Tribunal shall dispose of the appeal within the said period of stay specified in that order:Provided further that where such appeal is not so disposed of within the said period of stay as specified in the order of stay, the Appellate Tribunal may, on an application made in this behalf by the assessee and on being satisfied that the delay in disposing of the appeal is not attributable to the assessee, extend the period of stay, or pass an order of stay for a further period or periods as it thinks fit; so, however, that the aggregate of the period originally allowed and the period or periods so extended or allowed shall not, in any case, exceed three hundred and sixty-five days and the Appellate Tribunal shall dispose of the appeal within the period or periods of stay so extended or allowed:] [ Substituted by Act 22 of 2007, Section 75, for the provisos (w.e.f. 1.6.2007).][Provided also that if such appeal is not so disposed of within the period allowed under the first proviso or the period or periods extended or allowed under the second proviso, which shall not, in any case, exceed three hundred and sixty-five days, the order of stay shall stand vacated after the expiry of such period or periods, even if the delay in disposing of the appeal is not attributable to the assessee.] [ Substituted by Act 18 of 2008, Section 50, for the proviso (w.e.f. 1.10.2008).][Inserted by Act 41 of 1975, Section 59 (w.e.f. 1.10.1975).](2-B) The cost of any appeal to the Appellate Tribunal shall be at the discretion of that Tribunal.