Tribunal held that  the order of the Assessing Officer dated March 31, 2015 passed under section 143(3) mentioned that the sanction of the Commissioner of Income-tax was obtained for reopening of the assessment. According to section 151(2) as it stood during the period when the reopening was done, the sanction should have been obtained from an officer of the rank of Joint Commissioner. Such approval had not been taken. Since no proper approval was taken in accordance with the provisions of section 151, all proceedings subsequent to that point became a nullity. (AY.2007-08)