Held that  the reopening of assessment was for the specific purpose of assessing the escaped income. Therefore, in a reassessment proceeding, the Assessing Officer can only assess that income which has escaped assessment. The income which was subject matter of assessment in the original assessment proceedings or which was in the domain of the Assessing Officer in the course of original assessment proceedings certainly could not be considered in the reassessment proceedings. The Principal Commissioner could have exercised the powers under section 263 of the Act only in respect of the original assessment order passed under section 143(3) of the Act and not the reassessment order. The original assessment order had been passed on February 6, 2014 and the order of revision was passed on March 19, 2021.The revisional order was barred by limitation. (AY.2011-12)