Standalone net profit at Rs 6,318 crore, or Rs 19.5 per share, in April-June was 11.8 per cent higher than Rs 5,649 crore, or Rs 17.5 a share, in the same period a year ago.
The first quarter profit in the current financial year 2015-16 was highest since earning in October-December 2007.
Revenue fell 26 per cent to Rs 77,130 crore, hurt by a sharp fall in prices of crude oil and petroleum products, the company said in a statement.
Consolidated net profit rose 4.4 per cent to Rs 6,222 crore in April-June quarter of the current fiscal as opposed to Rs 5,957 crore a year ago, the statement said.
More From This Section
This was the highest gross refining margin it has earned in six year as compared to USD 10.1 per barrel margin in preceding January-March quarter and USD 8.7 of Q1 of 2014-15 fiscal.
The company, which is investing USD 12 billion to boost petrochemical capacity and refinery processes as well as build facilities to import ethane from US, said a 23 per cent dip in its turnover to Rs 83,064 crore was mostly because of 43.5 per cent dip in oil prices.
"The sharp increase in demand for transportation fuels helped us realize strong refining margins," Chairman Mukesh Ambani said.
RIL, which has in recent years invested in sectors like telecom, retail and financial services as it seeks to diversify revenue sources and reduce dependence on the country's heavily-regulated oil and gas sector, said its telecom venture, Reliance Jio Infocomm will be able to start full commercial operations in the next financial year.
Before the earning announcement, RIL shares fell 1.9 per cent to close at Rs 1,025.05 on the BSE.