If the IP phone is displaying “configuring IP”, how will you troubleshoot ?

Please check the DHCP pool allocated in your CME . If you are using CUCM go to System---> DHCP -----> DHCP settings and check the start and end IP add setting .

Also the TFTP server IP address have to be binded correctly.

Check your DHCP settings. Check TFTP IP

Actually I'm Using Cisco call manager10  

In Free Pbx setup  check the ip configurations 

Please you have to check the IP ADDRESS PORTION IN THE PBX TO TALLY WITH THE IP IN THE IP PHONE OR ASSIGN IP TO THE PHONE SO THAT IT CAN WORK PROPERLLY CALL ME ON