This is the terminal phase of Stethojulis trilineata (Bloch & Schneider 1801). The species is distributed in the Indo-West Pacific from the Maldives east to Samoa, north to southern Korea and Japan, south to eastern Australia and New Caledonia. S. trilineata has also been recorded from the Andaman Islands by Randall (2000), but not yet from subcontinental India. Additional information and a detailed description is found on page 36 in the following paper:

Randall, J. E.  2000. Revision of the Indo-Pacific labrid fishes of the genus Stethojulis, with descriptions of two new species. Indo-Pacific Fishes 31: 1-42, pls. 1-6.

Thank you sir your valuable identification.

Krishnan,

In the future you may find "FishBase" a valuable tool for fish identification:

https://www.fishbase.se/summary/Stethojulis-trilineata.html

Dear Krishnan Silambarasan

Stethojulis trilineata

Earlier phase of Stethojulis trilineata