Dear, your default code is 12345 but if you change then the way is use the flash box which is connected through your PC and then make is default code. Have a enjoy. Thanks
Dear,
You have to connect your phone with the pc and need a flash box then from there you can default your restore factory code which is 12345.If you haven't then please go to any mobile servicing center then asked them to restore your factory code. Thanks
check whether is locked for the network(airtel) If you by your phone on airtel offer it might be blocked by them (airtel). You need to format the software and reinstall the software.
You can open the restricted code by purchasing such code from any vendors online like SimpleUnlocking.com and have a lookup at this free guide for unlocking instruction
MobileUnlockGuide.com