You have to migrate from EMRALD SAPHIRE OR RUBY on to Platinum :)
You have to have a special Regigigas from an event.
Sorry dude, you can't get registeel in platinum without a cheat. But you can catch Regigigas in Platinum, but you'll need all three of the Regis to get him.
well, you actually have to get all the other regis from the gameboy games, then transfer them into platinum. if you want regigigas then you have to take one from sappire, ruby, and emerald, then go to the cave in snowpint city. there, all done!
yeah!!!!!!!
you cannot catch any regis in platinum you have to migrate them or trade for them but if you get regirock, regice, and registeel on platinum then you will be able to catch regigagas at level1 in the snow temple
You need relicanth and wailord to catch the regis in sapphire/ruby/emerald. You cannot catch the three regis in platinum unless you have the event Regigigas (this event has now ended). If you have the special regigigas in your party, three new caves will open up in Sinnoh and you will be able to catch the three regis.
you can't catch them in platunim you will need to migrate the from ruby sapphire or emerald
You can get regigigas by either trading it from the event before the release of platinum, or migrate the regis from ruby/sapphire/emerald, then go to the cave in snowpoint city, and catch it while you have all 3 of the regis in your party.
you go to pal park and download them into platinum, diamond, or pearel.
The only requirement to catch the 3 Regis is to have traded an event Regigigas to your Platinum from Pearl/Diamond. The players gender has no bearing on this at all.
you cant get all the regis only regigigas.
you can but you need 11 movie regigigas. if you have that you can go to some caves where the regis are. sorry i cant tell you EXACTLY where