At a first glance it looks like a silver-side fish, belonging to Atherinidae Family. You may diagnose to validate genus and species. Where was the species collected? Atherinids are mostly found in mangrove and river mouths, which has something to do with lower salinity than pure seawater.
Silversides (Atheriniformes) are commonly found in brackish water, freshwater and marine environments. There are reports of this genera from Gulf of Mannar, South east coast of India.