you can't. Giratina is in Diamond, so you can't transfer it onto Leafgreen.
Not sure who garatina is. I know that there is a Giratina in the turnback cave though.
you cant make an egg with Garatina.
You catch Garatina, Dialga,Palkiia,and all the lake Pokemon but mainly Garatina
it garatina
You dont
Garatina can be found in the spring path on Route 214 after you beat the Pokemon Leauge on regular Diamond and Pearl. If you have platinum, Garatina (origin form) is found at the spear pillar when you would normally go and capture Dialga or Palkia. If you go along with what ever goes on up there, you can go through the portal to the distortion world with Cynthia to capture Garatina at the end at I think it's level 47 for all of the versions. And that's where Garatina is located. :)
no thar isint
After you catch garatina,use fly to sangem town(or city) and talk to Professor Rowan I think he will give you something.After that you continue on your adventure.Hope you like it.
disortation world
I'm sorry giratina does not evolve.
In Turnback cave
its giratina not garatina and its available for capture in the turn back cave. you have to find 3 pillars then proceed to the next room and giratina awaits