"On balance, we expect the RBI to pause till December, with rising El Nino risks threatening the monsoon," the report said, adding that a "5 percent swing in food prices impacts CPI inflation by 250 basis points".

The RBI's target is to ease retail inflation, as measured by the Consumer Price Index, to 8 percent by January 2015 and 6 percent by January 2016. Both retail and wholesale price inflation accelerated in March due to rising food prices. While wholesale inflation rose to a three-month high of 5.7 percent, retail inflation inched up to 8.31 percent, after softening for three straight months since December.

The RBI had increased the key policy repo rate three times since Raghuram Rajan took over as Governor in September.El Nino refers to the warmer-than-average sea surface temperature in the central and eastern tropical Pacific Ocean. This condition occurs every 4-12 years and had last impacted India's monsoon in 2009, leading to the worst drought in almost four decades.

If El Nino occurs by summer, it will drive rain clouds away and impact the June-September monsoon. If it stretches to the fall, India will mercifully escape, it added.

PTI