The three legendary birds are next to the Orange Isle. To get there, go to Retazo City and continue Surfing east until you reach Ocean Isle. Just to get and extra master ball, go and find the trash can (believe me, it actually looks like a trash can). Keep talking to it (just keep pressing A until it gives you the master ball). Anyway, go to the east side of Orange Island and you can surf around - there should be three caves there, and there should be Zapdos, Moltres and Articuno in them.
I think Registeel is in the Power Plant (just off Veronica Town) with Raikou. Raikou's next to the generator, but I don't know where Registeel is...
You can't find registeel in Pokemon HeartGold.
You can't find Registeel in Pokemon Platnium. You just migrate it in Pokemon Ruby, Pokemon Sapphire, and Pokemon Emerald.
...You CAN'T!
by the mountain
cheek seribrii.net
you find it at map 5 or at that place with electric Pokemon
In the game Pokemon ruby destiny
You can find Registeel in the Ancient Tomb on Pokemon Ruby, Sapphire and Emerald. It can also be found in the Underground Ruins of Pokemon White2. To get Registeel in Pokemon White2 you need to catch or defeat Regirock and use the Iron Key reward to unlock the Iron Chamber containing Registeel.
u cant
you cant. you can only get registeel from Pokemon sapphire, emerald, and ruby.
Registeel,Regice,and Regirock are all Pokemon your required to migrate from their respective game(s).
To get Registeel you would have gotten the level 100 Regegigas from a wirerless event or migrate it from saphire, ruby, or emerald.