You need to either battle or obtain them
get National pokedex and the regis
national pokedex
u can if u have AR but u need national dex to get pal park to get regis from gameboy
The Regis are not found in the wild in HG/SS, you must trade them from D/P/Pt/FR/LG/R/S/E.
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.
To become the chosen one you must get the National Pokedex and all the regis
u import them from the hoenn games and catch regigigas in snowpoint temple after national pokedex
You have to have the National Pokedex, have someone trade you a Regigegas, then go to Iron Island, then Mt. Cornet, then look in the desert above the Resort area.
I'm pretty sure you can't get them in the wild; you have to transfer them from R/S/E. Or trade them, but that requires the Pokedex data on them.
You cannot find them, you need to migrate from one of your Pokemon games for gameboy.
You have to go into Snowpoint Temple but you first need to get the National Pokedex. Once you make it to the bottom, regigigas is there but he is a statue. You need a Nintendo event to be able to get all regis and regigigas.
I don't know where regiice is but you find regirock once you've defeated Cynthia twice and registeel in iron island when you get the national pokedex.