S. 154: Rectification of mistake-Mistake apparent from the record-Rectification order was passed after expiry of four years, holding that assessee was required to pay interest under section 234A,-ITNS-150 was an order under section 143(3), and any amendment to same would fall within scope of an amendment as contemplated under section 154(1)(a)-Rectification order was barred by limitation.[S. 154(1)(a), 234A]