In Mt. Coronet, between Eterna City and Celestic town.
The water to your right while going to Snowpoint City. Only
appears at 4 different tiles. They change daily.
If you want to find any more Pokemon or forget where Feebas
is go to
http://www.psypoke.com/
You can catch Feebas in Pokemon Omega Ruby in water, and by learning its evolved milotic form.
Illumise in Pokemon Omega Ruby can be caught in Zorua at the park.
Since Feebas is a Water Pokemon,you can only find it in lakes,rivers etc.
You have to transfer it from your Pokewalker. You get it on Icy Mtn. Road.
Plusle can be found and caught on Route 110.
the rarest Pokemon in Ruby Sapphire and Emerald is Feebas
sex with milotic
with a pokeball
feebas can be caught in any waters of route 199.
Illumise in Pokemon Omega Ruby can be caught in Zorua at the park.
trade it from ruby or sapphire
You can catch Skitty in Pokemon Omega Ruby and Alpha Sapphire in the barks of trees.
Minun can be caught in Pokemon Omega Ruby by seeking out these powerful Pokemon and then unlocking their incredible potential.
Feebas is in the area south from fortree city you must use a rod to catch it.
Since Feebas is a Water Pokemon,you can only find it in lakes,rivers etc.
You can catch feebas everywhere and occasionally barboach i am unsure where to catch magicarp but there is a way
You have to transfer it from your Pokewalker. You get it on Icy Mtn. Road.
Catch It In Cinnabar Island