Section 153(4)

(4) Notwithstanding anything contained in sub -sections ( 1), (2) and ( 3), where a reference under sub-section ( 1) of section 92CA is m ade during the course of the proceeding for the assessment or reassessment, the period available for completion of assessment or reassessment, as the case may be, under the said sub -sections ( 1), (2) and ( 3) shall be extended by twelve months.