Mystery gift
There are a lot of events on Pokemon Platinum.
You need to download it.
it already did i think
The only ways to get a Rayquaza in platinum are any possible events that have them or an Action Replay code
Nintendo events!!! google it
you have to download them at a Nintendo event
Only from events.
ar codes or Nintendo events
yes
No, it might be given out by Nintendo events or something
Arceaus (but you can only get it through events)
check serebii.net for info on upcoming events for Pokemon Diamond,Pearl,Platinum.