U Can't
you have to migrate him from Pokemon diamond after you get the national pokedex and go into stark mountain for the second time
you need lugia & Ho-oh :-P
The only way to get Heatran is to trade with pokemon Platinum,Diamond,and Pearl.
No, it is not wild
You can't. You need to get Heatran from Pokemon Diamond, Pearl and Platinum and then trade to heartgold and soulsilver.
Heatran is unobtainable (and therefore does not exist) in PoKéMoN HeartGold & SoulSilver, so you'll need to trade it from PoKéMoN Diamond, Pearl or Platinum.
You cannot catch Heatran in Pokémon SoulSilver, you will have to trade for it.
You need Ho-oh and Lugia
you cant catch it in soulsilver. you have to trade it from diamond pearl or platinum.
catch other Pokemon
trade with someone with diamond pearl platinum or use hacks
you can't. if you want one, trade it with diamond/pearl/platinum
The only way to obtain a Heatran in Pokemon Heart Gold/Soul Silver is to trade it.