latios,latias,raquazza,kyogre,groudon,regice,registeel,regirock
catch them :P
It is very rare but you can catch it at mount Pyre.
you can catch sudowoodo and smeargle
Route 119(rare)
latios and latias appear in random patches of grass and areas of water after you catch Rayquaza or make him faint.(after saving the world in Sootopolis.)
You can't catch a Gardevoir in Pokemon Emerald. To obtain one you can catch a rare Ralts on Route 102 and evolve in into a Krilia, and then a Gardevoir.
On Route 116. Rarity: Rare.
You catch it in the Victory Road, but it is super quadriple rare!
underwater routes 124-126,but rare.
Underwater near sootopolis city its rare though.
it's just by luck
The rare Pokemon on emerald are Rayquasa, kyogre (hard to catch), groudon (hard to catch), ho-oh, lugia, sudwodoo, smeargle and metagross. Regirock, regiice, registeel, latais, latios, mew, deoxys, and serribi.