You cannot catch Celebi in Pokémon XD.
You Can Catch Celebi Only If You Trade From The GBA System
You cannot catch Celebi in Pokemon Diamond.
yes you can. but only certain times he will be in front of the relic.:)
You Cannot actually get Celibi on Either Colosseum or XD: Gale of Darkness, However you can Get Celibi on Pokemon HeartGold and SoulSilver. In Pokemon Colosseum if you use The Flute Thing that purifies Pokemon Celibi will come to Purify Your Shadow Pokemon. I'd Reccommend using it on Something like Metagross, Tyranitar or Raikou or something like that.
You can't other wise you have to trade from Pokemon Collosium
you get celibi
you cannot catch wild rare Pokemon in xd but you can catch the trainers rare Pokemon, if they are "inpure"
you can get celibi on heartgold only from a wi-fi event
You can't catch it.
Rayquaza is not avaliable in Pokemon XD
no.
No, you can't catch Groudon in Pokémon XD.
to do this you have to catch all of the unknown and talk to the wall and he will appear randomly on the game. Hope i helped.