Indian Oil Corporation, the nation's largest oil firm, on Tuesday reported a 67 per cent jump in its March quarter net profit on the back of a recovery in fuel marketing margins and better refining margins. Standalone net profit was at Rs 10,058.69 crore, or Rs 7.30 a share, in January-March compared with Rs 6,021.88 crore, or Rs 4.37 per share, in the same period a year back, according to a company's stock exchange filing.