Vulpix is not available in HeartGold. You can, however, find a friend who has SoulSilver that will be willing to trade with you, or you can go on the GTS
You can't find registeel in Pokemon HeartGold.
You can find it in Pokemon Platinum, Pokemon Crystal, Pokemon HeartGold, and Pokemon SoulSilver.
unkowns {pokemon}
You cannot find Latios in Pokemon HeartGold unless you went on wi-fi and got the Enigma Stone
There is no such thing.
You can't
yes
trade
You can't
Just find them!
You can't do it.
Find and then catch