Well saw this on a fish group on facebook. Noone can give a decent answer so I came to you guys hoping you can help us? The one who posted lives in the Philippines and he said he caught it in the river that is somewhat connected to sea.
This fish called neon velvet damsel fish (Neoglyphidodon oxyodon)
2$\begingroup$ I don't think this is right. The asker's fish has a brown tail, no golden spot/stripe on its back and very different "fluoro" markings. The asker's fish was caught in a river but yours lives in the sea. $\endgroup$ Apr 5, 2019 at 19:37
$\begingroup$ @DavidRicherby maybe if the asker added many pictures from different sides, I can see the blue color under the fish eyes which says everything .. $\endgroup$– MuathApr 5, 2019 at 20:27
2$\begingroup$ There's only one photo available and it already shows significant differences from your suggestion. Having more photographs of the unknown fish can't make it look more like a neon velvet damselfish. $\endgroup$ Apr 5, 2019 at 20:30