Mumbai, April 25 -- Reliance Industries Ltd posted a 13% fall in its profit for the January-March period as the US-Israel-Iran war weighed on the firm's key oil-to-chemicals (O2C) segment, even as contributions from telecom and retail segments remained resilient. Its oil refining business was plagued by higher oil prices and expensive shipping and insurance costs due to the war. Higher fuel cracks-the margins the firm makes from refining crude into fuel-helped offset some impact of the high input costs. Incomes from Reliance's telecom and retail businesses offset the dip in the key O2C business to deliver a flattish operating income at a consolidated level. In a press release on Friday, Mukesh Ambani, the chairman and managing director of R...