was kaname adopted door jury?

Nope, Kaname, when awakened door Rido, ate the real Kaname, (Yuki's real brother) and took his form as a baby because he didn't have enough power to be in his original form. His "parents" still thought he was the boy Jury actualy gave birth to, and yuki also didn't know this untill he told her when they run away from Cross/Kurosu academy when Yukis identity as a vampire is revealed. He basicaly tells her his whole history. lol :)

In a way, yes.

Rido killed Kaname, Yuuki's real older brother, in order to use his blood to awaken the family ancestor, also named Kaname. When Yuuki's father (sorry, I've forgotten his name), found out, Rido hoped that the ancestor would kill him in his bloodthirst after having spent centuries asleep. However, Ancestor Kaname chose to revert back to an infant instead. In that state, he was small enough to control the thirst. Yuuki's parents then adopted him and he replaced their dead son. Only they and Rido knew, at first. Kaname began remembering as a child, and he later told Yuuki during the manga.