Although victorious, after the June 326 BC battle of Hydaspes - near the northernmost of the five great tributaries of the Indus River - Alexander was pressured by his generals to end his Asian conquest and to return to Babylonia.
In all probability, the earthquake of 325BC occurred along the Makran coast (of present southern Pakistan) and generated a destructive tsunami.
Another possibility is that the 325BC earthquake occurred in the Gujarat region, where large events are also known to occur - particularly along the Kutch Graben region or even near the Bombay graben.