Wait... I'm so sorry I was thinking of a different Pokémon. Complete brain fart. No, I don't think you can catch Frillish in X and Y.
Once again... sorry.
you can however catch frillish in black and white or its counterparts but it will be a few months before poke bank opens and move em from that. --- They literally gave him the keys to the kingdom and he pissed it all away--dragonballer88