The river in Route 119. You better be really patient, because Feebas can only be found on two tiles in the whole river. And even then, it's not certain to appear.
you can find a feebas in route 118 and 119 but its hard to find
You must evolve Feebas.
On the Route southwest from Fortree City.
you can get feebas on route 119 very rare
Only in ruby, sapphire and emerald at route 119
I know in Sapphire it was REALLY hard to find Feebas (Milotic's basic stage).
Feebas can be found by fishing in route 119. It appears only in six random squares.
the only way to evolve it is to have the feebas at a high BEAUTY status for Pokemon contests. and the best way to do this is to have a feebas with a MODEST nature.
trade it from ruby or sapphire
Milotic cannot be seen in sapphire you must catch a feebas feed it blue pokeblocks until its beauty is at the max then train it one level and it will evolve to milotic feebas can be found alittle southwest from fortree city you must use any rod to get it.
You Have to migrate a Feebas from Pokemon Ruby, Emerald or Sapphire, Max out it's friendship and it will evolve into a Milotic,
Since Feebas is a Water Pokemon,you can only find it in lakes,rivers etc.