S. 151: Reassessment-Sanction for issue of notice-Competent authority-Approval granted by the Principal Commissioner was therefore not a valid sanction, and the consequential notice under section 148 and assessment order passed under section 147 were quashed. [S. 148A(b), 148A(d), 151(2), the Taxation and Other Laws (Relaxation and Amendment of Certain Provisions) Act, 2020, S.3, Art. 226]