Only ruby, sapphire and emerald can catch registeel trade one from those games to leafgreen.
Registeel is not catch able in Pokemon LeafGreen. In order to get a Registeel you will need to trade for one from Pokemon Ruby or Sapphire.
You cannot catch Registeel in Pokemon LeafGreen. This is due to FireRed and LeafGreen being able to trade with Ruby and Sapphire. Pokemon Ruby and Sapphire have the three legendary golem Pokemon including Registeel.
You can only get registeel in ruby and sapphire and emerald.
you cant
Trade it from ruby, sapphire or emerald.
no you can not
You can not catch it in leafgreen,but in firered you can.
You can not capture him in pokemon black
no you can, you most catch it in Pokemon emerald
Nowhere no hoenn Pokemon can be captured in leafgreen.
You do not need a Wailord to catch a Registeel in Pokemon Emerald. You may need a Wailord or any other water-type Pokemon to surf to the place where you catch Registeel, but other than that, you don't need a Wailord.
Catch 'em all