Tribunal held that provisions of section 35(2AB) read with rule 6 clearly mandate filing of Form 3CL and limit weighted deduction to 150 per cent of eligible expenditure incurred on in-house research and development from assessment year 2018-19 onwards. Since Assessing Officer allowed deduction at 200 per cent in clear contravention of law, and without verifying whether basic condition of submission of Form 3CL by DSIR quantifying eligible expenditure had been fulfilled, Principal Commissioner was justified in invoking revisionary powers under section 263 and setting aside assessment order with a direction to Assessing Officer to frame a fresh assessment after conducting proper verification and affording reasonable opportunity to assessee. (AY. 2018-19)