Held that   the issue raised by the assessee in the additional grounds was a legal issue challenging the validity of notice under section 148 of the Act even when the Assessing Officer had the time to issue notice under section 143(2) for conducting regular assessment. The additional grounds were directly connected with the validity of reassessment proceedings and no new facts needed to be investigated for adjudicating them. The additional grounds raised by the assessee in both the years under consideration was admitted. That the assessee had not filed its original return under section 139 of the Act. However on receipt of the notice under section 142(1), the assessee filed the return of income on December 2, 2016 for both years. Under such circumstances, according to the law during the relevant years, the Assessing Officer had six months from the end of the financial year in which such return was filed to issue notice under section 143(2) of the Act. In this case he had time to issue notice under section 143(2) till September 30, 2017 to conduct regular assessment under section 143(3) of the Act. However, notice under section 148 of the Act was issued to the assessee for both assessment years on June 22, 2017. As on the date of the issuance of notice under section 148 of the Act the original assessment proceedings were pending as the time period for issuance of notice under section 143(2) had not expired. Section 142(1) and section 148 of the Act cannot operate simultaneously. There was no need for the Assessing Officer to issue notice under section 148 as there was time to issue notice under section 143(2) of the Act for conducting the assessment under section 143(3) of the Act. Accordingly, the notice under section 148 by the Assessing Officer for both the assessment years is  quashed.(AY.2014-15, 2015-16)