While playing through the story you will end up in the distortion world with Cynthia. in the distortion world you will have to battle Cyrus after beating him Cynthia will heal your Pokemon. then you will be able to find giritina, in the distortion world.
catch girtina
You need to battle Girtina in the Reverse \World then you will be able to go to Sunnyshore
They give you a model of giratina,but no they don't make you get girtina in the Game.
You should wait for Gold and Silver to come out Platinum is about the same except for Girtina and you get both Dialgia and Palkia.
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.
buy the Pokemon platinum book
The 151st Pokemon is Mew and is unobtainable in Pokemon Platinum.
no you can't find a torchic egg in Pokemon platinum
try your best to find spirtomb in Pokemon platinum
There is not a route 233 on Pokemon platinum.
You cannot find zekrom in pokemon platinum
you find them in the cave