How to ring some ext fro calls from N port

Hi I hve installed Asterisk Now Beta 6, have instaled 2 board in my pc with 2 and 4 fxo chips… i want to put a rule that when call came from port 1 and 2 rings ext 1 to5 when call came from port 3 and 4 rings ext 6 to 10 and when call came from port 5 and 6 rings ext 11 to 15…
thanks in advance