I have pokemon soulsilver and i went to this website and it said legendaries in Kanto and Sinnoh and Hoenn?

In SoulSilver you will receive the National Pok�dex from professor Oak after beating the Elite Four, you are then able to travel to Kanto and challenge the Gym-leaders there. Sinnoh and Hoenn are inaccessible, unless you use the Pok�walker after receiving the National Dex.