To receive pokemon requires a Pokemon Bank subscription which costs $6.50 per year. You can receive these Pokémon only once per Pokémon Bank account, even if you have multiple copies of Pokémon X, Pokémon Y, Pokémon Omega Ruby, or Pokémon Alpha Sapphire.
Each of the three Pokémon that you receive has a Hidden Ability, a trait they do not possess when found in Pokémon Omega Ruby and Pokémon Alpha Sapphire.
To Receive Pokemon:
Open Pokemon Bank.
Select "Use Pokemon Bank".
Select Game.
Gifts will be received.
Save and Quit.
Open game which was selected in Pokemon Bank.
Select POKEMON LINK from the start menu.
Select Yes.
Data from the Pokemon Bank will be retrieved and the pokemon transferred to a box in your PC.
Pokemon
Regirock
With the Hidden Ability Sturdy, if Regirock has full HP and is hit with an attack that would normally knock it out, it will be able to endure the hit with 1 HP remaining. This is a great Ability for Regirock to have, being a Rock type with many weaknesses.
Level: 50
Ability: Sturdy
Moves: Explosion, Ice Punch, Stone Edge, Hammer Arm
Regice
Regice's Hidden Ability Ice Body allows it to restore HP when the weather condition is hail. Regice is strong against opponents that attack it with special moves. By using Hail, it can recover HP throughout the battle while doing even more damage!
Level: 50
Ability: Ice Body
Moves: Thunderbolt, Amnesia, Ice Beam, Hail
Registeel
Registeel's Hidden Ability Light Metal reduces its weight by half. This decreases the damage it will take from moves such as Low Kick and Grass Knot that are more powerful the heavier the target is. It is especially good for Low Kick, a Fighting-type move that is super effective against the Steel-type Registeel. Roll with those supereffective punches and strike back!
Level: 50
Ability: Light Metal
Moves: Iron Head, Rock Slide, Gravity, Iron Defense
Geez, back in the Sapphire/Ruby days on the GBA I got these guys for free..