Failure to furnish return in search cases: amendment clarifies cross reference to sub section and its applicability provision. The provision inserts the words 'sub section (1) of' after 'clause (a) of' in section 276CCC so the penal provision expressly refers to clause (a) of sub section (1) of section 158BC, clarifying the statutory cross reference that governs failure to furnish return in search cases, with effect from the stated commencement date.