S. 254(2): Appellate Tribunal-Rectification of mistake apparent from the record-Department’s appeal rendering decision in favour of assessee based on law existing on date-Subsequent decision of Supreme Court in favour of Department would not render decision of Tribunal liable to rectification on ground of mistake-SLP of revenue dismissed-Revenue filed Miscellaneous Applications for rectification before Tribunal beyond statutory six-month limit prescribed under section 254(2) without any condonation application-Tribunal lacked power to condone such delay and its order allowing those applications stood vitiated as being passed beyond limitation-SLP of revenue dismissed. [S.36(1)(va), Art. 136]