You can use the GTS :P
There is no deoxys in Pokemon platinum... u could only migrate to pal park from 3rd generation. :)
go to pal park
You need to migrate it from FireRed, LeafGreen, or Emerald. But if you have a Deoxys in Pokemon Ruby or Sapphire, then you can migrate from them to Pal Park.
no. If you have a Pokemon gameboy game migrate deoxys onto platinum and go to pal park on rt 221 and find it in the grassland area.
you have to upload it through pal park from your leaf green or fire red. then catch it in pal park.
You must transfer it from you GBA games and then capture it in the Pal park located in Platinum.
Once you beat the Pokemon league,turn off the game it will say migrate from emerald,sapphire,ruby,etc click on it have emerald,sapphire,ruby,etc in the GBA slot if you have deoxys migrate it go to pal park and catch it.
You can get Deoxys in Pokemon FireRed, LeafGreen, and Emerald by using a GameShark, for the Nintendo event has expired. In Pokemon Diamond, Pearl, and Platinum, you will need to transfer Deoxys from any of the GBA games to the Pal Park, or simply trade with a friend who has it.
I don't think there is a code. But i know a few methods to get the Pokemon. 1.you can trade it from Pokemon Platinum,Pokemon Diamond,or Pokemon Pearl. 2.In Pokemon,Platinum,Diamond and Pearl there is a Pal Park,(You need national dex),which you can get your old Pokemon from LeafGreen,FireRed,Ruby,or other Role-Playing Pokemon games. 3.there is a code,a Pokemon modifier,were you can get Pokemon 1-493. I hope i helped if you look on Google for "heartgold deoxys ar codes" it should be the 5th link
Deoxys is not a Pokemon you will be able to capture in this game. As far as I know you could only get it in the GBA games through mystery gift. If you did happen to get that mystery gift, then you can transfer it through pal park.
you can using cheats,trade or using pal park but without 1 of those 3 u cant
To get your emerald Pokemon to platinum you transfer them in pal park.