if you mean wailmer its almost everywhere
in a route
You can find trainer Conor near Route 132
Look on Route 214 with Emerald in the lower slot.
You find Skarmory on Route 113 at level 16, 5% of the time.
Only in ruby, sapphire and emerald at route 119
route 228
You can find Volbeat on Route 117 in Pokemon Emerald Version.
In Emerald you can find Skitty on Route 116, but they are rare.
On Route 102
in a route
route 102
Route 119, 124
You can find it at route 117
You can not find a Gardevior on Emerald. You will have to find a Ralts in route 102 then evolve it into Kirlia at Level 20. Then into a Gardevior at level 30.
All i know is on route 109
In Ruby, Sapphire and Emerald on Route 116 and are rare.
route- 124, and 126. you have to be underwater though