If your Nokia 6280 is asking for restriction code means it is locked to some particular network.So to use it in all network you need to unlock it.
Unlocking your phone can be done with the help of http://www.simpleunlocking.com/nokia-6280/rs16wp9/ where you need to mention your network and country your phone is locked to.They provide you with unlock code and free unlocking instructions.
You can use any service provider to unlock your phone.