you have to have the national Pokedex
You get it in the Snowpoint Temple.
You have to have regice, regirock and registeel. Then go to the snowpoint temple.
Regigigas is Pokemon #486 on Pokemon Platinum. To get it, go to the Snowpoint Temple with Regirock, Registeel, and Regice.
you have to have regice,registeel,and regirock in your party then go to the snowpoint temple in snowpoint city and go all the way down to the bottom of the temple and regigigas will be there
Go to the cave in Celestic town,then go to the Snowpoint temple.
you need the three regis then go to snowpoint temple after beating the game
u have to get all three regis and then go to the temple in snowpoint city
get all 3 of the other regi's data in your pokedex, beat the snowpoint city gym, and go into the temple in snowpoint city
You must have the move anywhere code for platinum. Go to snowpoint city and then go to snowpoint temple and walk around the lady. Go to 5f where the regigas statue is and there should be a boulder next to the wall. Then there will be the cave entrance.
you have to get regirock, regi ice, and registeel and go to the temple in snowpoint city but you have to beat the elite four first. (:
First, you have to get all three regis, then you go in snowpoint temple, go to where the "statue" is and it will be a regigias. Finally just talk to it.
To get Regigigas in Diamon, Pearl or Platinum, you must go to Snowpoint temple with all 3 of the other regis: Regirock, Registeel and Regice. These can be obtained by transferring them from other Pokemon games such as ruby, sapphire and emerald :)