Darkrai is an event Pokemon, and cannot be found through normal game play. Darkrai thus cannot be found in SoulSilver. Darkrai was an event Pokemon that was available for Diamond and Pearl, but not for SoulSilver.
Nope. sorta. trade it from Pokemon dimond [if u went to the event!] unless u cheet! You can't capture darkrai in the wild but you can on pokemon diamond and pearl if you have cheats. no darkrai is not in soulsilver