Revenue recognition: tax ICDS restricts methods while Ind AS uses a control and performance obligation model affecting timing. Divergent revenue recognition frameworks govern taxable income computation under tax oriented ICDS IV, AS 9 and the control based Ind AS 115, producing different timing and measurement rules for contract and service revenue. ICDS IV limits permissible methods for tax computation-disallowing completed service contract recognition for services, including retention money in contract revenue for tax purposes, and constraining early-stage recognition to costs incurred until a prescribed stage-while Ind AS 115 requires identification of distinct performance obligations, allocation of the transaction price by stand alone selling price, and constrained recognition of variable consideration to amounts unlikely to reverse.