INS Cuddalore, a Pondicherry - class vessel that was decommissioned in March.
It will be turned into India's first underwater museum off the Puducherry coast, as per reports.
The vessel will be deployed on the seabed at a depth of 26 metres, seven kilometres off the coast.
The 60 - metre - long vessel will be a destination for scuba diving and snorkelling, reports said.