Petitioner-company undertook a demerger of its Power Transmission and Power Distribution business into a resulting company under an NCLT-approved scheme and filed an original return under section 139(1) and thereafter a revised return after NCLT approval took effect. Separately, an NCLT-approved amalgamation of NAPL with petitioner was undertaken, and to give effect to this amalgamation, petitioner furnished a modified return under section 170A. Assessing Officer issued a notice under section 143(2) selecting the revised return for scrutiny. Petitioner intimated filing of modified return under section 170A and requested completion of assessment in accordance with section 170A(2). Assessing Officer then issued a further notice under section 142(1) raising 16 queries. Petitioner furnished comparative computation and tax audit report details. Assessing Officer thereafter passed the assessment order. Subsequently, fresh notices were issued, one under section 143(2) and another under section 142(1). On writ, the petitioner submitted that post-completion of assessment that considered the modified return under section 170A, the Assessing Officer had become functus officio and lacked jurisdiction to reassess the same matter by issuing fresh notices. Court held that, at least prima facie, there was substance in the argument of petitioner that the Assessing Officer could not have issued a fresh notice under section 143(2) for the very same year, seeking to assess income on the basis of the modified return of income submitted under section 170A. Accordingly, the petitioner had made out a strong prima facie case for grant of ad-interim relief. (AY. 2023-24)