It depends what game you have. In diamond/pearl you can't. In platinum, if you make it faint (not kill, Pokemon can't die) you cab't catch it, BUT you can catch again its its ALTERED FORM (which looks cooler).
if you dont catch giritina but you kill him, you dont have another chance enless you saved the game right before you tryed to catch him
In Pokemon Diamond and Pokemon Pearl, there is no possible way to catch a Giritina. You can, however, either catch one in Pokemon Platinum or trade with someone who does have one. In Pokemon Pearl, you catch Palkia at Spear Pillar. In Pokemon Diamond, you catch Dialga at Spear Pillar.
Mespirit Azelf Uxie Heatran Palkia Dialga Giritina (Both Form) And some other Nintendo events one
In platinum you can catch Giritina, Palkia , Dialga, Heatran, Moltres, Arcticuno, Zapdos, Cressilia, Uxie, Mesprit, Azelf, and Regigigas. With the action replay you can also get Shaymin, Darkrai, and Arceus.
Yes you can rematch greevil at anytime and he will still have his shadow Pokemon if you defeated them.
No, only pass the part with Giratina. You don't have to catch it. U can still catch giratina in disortation cave.
you could get a giritina from a trade or action replay
no
if you dont catch giritina but you kill him, you dont have another chance enless you saved the game right before you tryed to catch him
you need to beat or catch giritina.
After you catch giritina youll come to spring field and it will be there in the grass!
go to turn back cave
Im sorry but no
giritina, palkia and dialga
you have have to catch giritina at the spear pillar on mt coronet
trade for it, but kinda unlikely, or catch it if you are a gold member.
Transfer the Arceus from Platinum that was released in a special event.