Assessee filed its income tax return for relevant year, however, inadvertently omitted to make claim for deduction under section 10B in respect of two 100 per cent Export Oriented Undertakings (EOUs), which according to him were eligible for deduction under section 10B.  Assessee, during assessment proceedings, filed letters claiming for deduction under section 10B in respect of aforesaid units, however, Assessing Officer refused to consider this claim for deduction, on ground that such claim was not raised by filing revised returns. Commissioner (Appeals) as well as Tribunal upheld order made by Assessing Officer. On appeal the Court held that Appellate Authorities may confirm, reduce, enhance or annul assessment or remand case to Assessing Officer, because, unlike an ordinary appeal, basic purpose of a tax appeal is to ascertain correct tax liability of assessee in accordance with law.  Therefore Commissioner (Appeals) in exercise of his plenary/co-terminus powers, as well as Tribunal, ought to have entertained claim for deduction under section 10B as all necessary facts were already on record. Appellate Authorities could not have refused to consider assessee’s claim for deduction on ground that such claim was not made in original returns or revised returns filed before Assessing Officer. Followed   CIT v. Pruthvi Brokers & Shareholders [2012] 349 ITR 336 (Bom.)  (HC)  Referred Circular  No. 14 (XL-35 of 1955 dt 11-4-1955. (AY.2005-06)