The 34-year-old tourist, identified as Nikkittin Surgey, had sustained cut injuries on his head, hands and legs as he resisted a four-member gang which attacked him with sickles on Friday.
Inspector Prabhakaran said the three arrested persons have been identified as Ganeshkumar (24), Mariappan (32) and Anand (33). They are natives of Therkkupoigainallur in Velankanni.
The gang had fled the scene snatching his camera, currency notes and a mobile phone.
One person is still absconding, police said.