Tamil Nadu  conceded that fishermen stray into the Sri Lankan waters, justified their action stating that the poor fishermen had no other go and they had to eke out their livelihood. 
They could not be deprived of their traditional fishing grounds in the Palk Bay by imposing artificial restrictions such as International Maritime Boundary Line.
"The legalities or sovereignty of nations do not bind the poor and innocent fishermen just like fish which have no trans-boundaries… 

Any decision or stipulation that harms the traditional fishing practices in the Palk Bay will deprive thousands of fishermen, and also the families that indirectly depend on fishing profession, of their right to livelihood and make them starve”

Chief Secretary Debendranath Sarangi thus replied to a PIL in court.

details of distance between the IMBL and different villages
 minimum distance 9 nautical miles from Dhanushkodi
 maximum  34 nautical miles from Devipattinam. 
One nautical mile is approximately 1.85 kilometres.

As per the Tamil Nadu Marine Fishing Regulation Act 1983, mechanised fishing boats could fish only beyond 3 nautical miles from the coast. “The area, thus available for fishing near Rameswaram (Dhanushkodi) is only 6 nautical miles portion. No proper fishing grounds are available in the area which also has rocks and coral reef.“Hundreds of fishermen have to lay their nets in the limited area. When the nets are laid, drifting is inevitable (as a sweep area of about 2 square kilometres is required for fishing) due to wave action or water current and thus the boats naturally tend to cross the IMBL…

 167 incidents of shooting as well as attacks on Tamil fishermen had taken place since 1991, the State said that 85 fishermen had died and 180 suffered injuries. Similarly, 146 boats and 746 Tamil fishermen were apprehended by the Sri Lankan Navy since 2006. Of them, 131 boats and 741 fishermen were repatriated.

“the inhumane action of the Sri Lankan Navy in shooting, manhandling or assaulting” Tamil fishermen was against the United Nations Convention on the Laws of the Sea 1982 which states that fishermen apprehended by a foreign country on charges of poaching or illegal fishing should be treated in a humane manner

Katchatheevu, a small barren uninhabited island spread over 285.2 acres in the Palk Strait off Rameswaram, was part of India historically, two maritime agreements entered between the Centre and Sri Lanka in 1974 and 1976 ceding away the island and the adjoining seas was the root cause for the problems faced by Tamil fishermen.

The probable solutions to the problem ((as suggested by TN Government))
 re-examining those two agreements
Centre could get Katchatheevu and adjacent seas on ‘Lease in Perpetuity' for fishing and other associated  activities

Such a move would serve the double purpose of upholding Sri Lanka's sovereignty as well as permitting Tamil fishermen to carry on their vocation without any problems.

implementation of ‘Licensed fishing method' through which licensed Tamil fishermen could be allowed to fish in Sri Lankan waters up to five nautical miles.

 international treaties signed between various countries such as China and Japan, Australia and Indonesia, China and South Korea and China and Vietnam for granting traditional fishing rights to fishermen in disputed waters 

 the Centre could provide such rights to Tamil fishermen
(( words ‘traditional rights' found in the 1974 agreement are claimed to not include fishing rights))