The company found natural gas in two of three test wells drilled in the Mannar Basin, off the island's north-west coast, called the CLPL Dorado- 91H/1z well and the CLPL-Barracuda-1G/1 well.
The third well, CLPL-Dorado North 1- 82K/1 was plugged and abandoned as a dry hole on 14 December, 2011.
Rahul Dhir, chief executive of Cairn India, said the firm had acquired additional 3D seismic in a 600 square kilometer area and entered a "second phase of exploration".
A "potential commercial interest notification" has been submitted to Sri Lankan authorities under its agreement with the country, Dhir said in a quarterly review.
Typically, an oil firm will dig exploration wells and following further seismic tests will drill an 'appraisal well" to find flow rate of hydrocarbon and extent of the deposit and determine the commercial viability of a discovery.
After a find has been declared to be commercially viable, actual production wells will follow.
An official at Sri Lanka's Petrol