"The Indian Coast Guard ship Sagar in a swift anti- poaching operation apprehended one Sri Lankan fishing boat Kapila Putha with six fishermen," a Coast Guard release said.
The boat was spotted about 158 nautical miles north east off Chennai at 2.30 pm.
The boat was apprehended for violations under Maritime Zones of India Act 1981, the Coast Guard said.
The boat along with the crew were being escorted to Chennai and they will be handed over to police for further legal action, it said.