You can get Shaymin at special events. Unfortunatly, Shaymin's event has passed, and it may be awhile before they are distributed again. Sorry.
just trade it with me i have one from my friend
use an action replay
you need the Nintendo event
You can't get the Miracle Berry without the Shamin event.
If by "shamin" you mean "Shaymin", then you can't. It must be traded from Pokémon Diamond, Pearl, or Platinum.
http://www.serebii.net/platinum/battleroulette.shtml
Through an event or Action Replay codes
platinum only
You need the Key Item Oak's Letter to get Shaymin.
you hve to hack or through a special event that i think has passed
No, you can't. To get it, you must trade from any of diamond, pearl, or platinum.
i have shamin