No. You have to transfer them from your emerald game. If you get all three Regis and transfer them over, you unlock regigigas. He is in the snowpoint temple. You have to get the national pokedex before you can do any of this.
You cannot catch any of the Regis (Regirock, Regice, Registeel and Regigigas) in Pokémon HeartGold or SoulSilver.
you can't- make Pokemon migrate from Pokemon ruby/sapphire/emerald or trade from diamond and pearl or platinum.
you don't
No, you cannot catch Kyogre in "Pokémon SoulSilver."
no it is not possible
if you what the regis you have magrate from emelerd or shappire and the other one that how you get the Pokemon
You can't catch bastiodon in Pokemon soulsilver.
You must trade from Pal Park
You cannot catch Heatran in Pokémon SoulSilver, you will have to trade for it.
No, you can not catch Phanpy in SoulSilver. It is a version exclusive to HeartGold.
You are not able to catch the regis in Diamond. You can catch them in the Game Boy Advance version of Pokemon Emerald.
catch it? no.