Just go to a union room in both games and offer to trade
How you would trade to any other Pokemon game.
You can't you would have to catch one in Pokemon Heartgold or Pokemon Soulsilver and trade it to Platnium
trade three pokemon from soulsilver to platnium its that simple talk to the people
trade it from pearl, diamond, platnium, heartgold, soulsilver :-p
to trade any thing any where you need 1 badge then youll be able to trade just beat roark hes extermly freaking easy and how you get a sterter in Pokemon soul silver professer elm gves you one at the start and Pokemon platinum professer rowan gives you one from the start
The only way to get the Sinnoh starters in Pokemon HG/SS is to trade it from games Diamond, Pearl, and Platinum.
arceus. you have to trade over from either pearl, diamond or platnium, palkia, dialga and giratina to either heartGold or soulSilver.-RR14
Trade them over from Diamond or Pearl! i got all the sinnoh starters from my friends! :D
you cant catch it in platnium but you can trade it
1. you can get them in trade. 2. action replay. 3. hacking.
you don't, you only can trade from platinum (and others such as Soulsilver and Heartgold etc.) to black white)
you cant get it in sinnoh you can only get it in Pokemon emerald version, or if you have kyogre in heart gold trade it to soulsilver and you will encounter a rayquaza i don't know where but it will be at level 50 i think. Or you can trade groudon from soulsilver to heart gold and encounter rayquaza