Which among the following in India are known for substantial coral reef formations?

1, 2, 3 & 4
Occurrences of Coral Reefs in India The major reef formations in India are restricted to the Gulf of Mannar, Gulf of Kachchh, Andaman and Nicobar and Lakshadweep Islands. Scattered coral growth has also been reported along certain inter-tidal belts and submerged banks both on the east and west coasts of the country. The reefs at present are important to the local community only to the extent of sustenance fishing. Tourism is being developed at some places though local communities do not benefit much from the revenue generated. The health of corals, as deduced from the literature records since 60s has been on steady decline mainly due to stress from anthropogenic pressures and interference.