Sluggish economic activity and a fall in production at core industries dragged it lower, poll participants said.
Annual infrastructure output growth, also referred to as core industries, shrank 0.1 per cent in March due to lower cement and steel production, government data showed last week.
The core industries - coal, crude oil, oil refining, steel, cement and electricity among others - account for more than a third of overall industrial output.
Weak global demand, especially from major export destinations like Europe, also weighed on Indian factories. Exports have been sliding since September and fell a whopping 21.06 per cent annually in March.
"Against this backdrop we expect domestic economic activity to have remained subdued in March," said Bharti Bhargava, regional economist at 4CAST.
The poll suggested inflation eased to 4.9 per cent in April from March's three-month low of 5.2 per cent, comfortably below RBI's target of 6 per cent by January 2016.
Although recent untimely rains damaged crops, raising concerns about a sharp rise in food prices, its impact has not been felt so far as the government might be offsetting some of the loss in output by releasing stocks.
"The likelihood of soft international commodity prices, including oil, as well as the persistence of subdued core inflation is likely to mean that headline CPI remains below the RBI's target of 6 per cent," said Jyotinder Kaur, principal economist at HDFC Bank. "We expect inflation to average 5.4 per cent over fiscal year 2016, that should keep space open for repo rate cuts of another 50 basis points over the course of the fiscal year."