Pixelmon Mod

First of all I'm sorry if this is in the wrong section...
I wanted to start a server but first I wanted to know how can I make a certain area where players can't send out their pixelmon.
Like they won't be able to send out their pixlemon in mart like places but when they get out of it about 5 blocks they can.
Or instead of mart in a town or something.
Thanks for help.

I believe claim plugins can cancel the event that fires when throwing a ball inside a specific claim. Don't know enough details to comment further though.