You will not be able to have the phone unlocked unless you are a customer. Your uncle may be able to have them unlock it depending on whether he was pay as you go or monthly and assuming his account was/is paid in full.
From the Orange site:
All Orange phones are locked so that they can only be used on the Orange network.
You can have any handset unlocked to use on any compatible network. Once a handset has been unlocked it can be used with an Orange SIM and/or any other compatible network SIM.
pay as you go
In order to have your phone unlocked:
- The IMEI must not be blacklisted (customer services will check this for you).
- The phone needs to be active, you can't unlock an old pay as you go phone that's no longer on an active account.
- The handset to be unlocked must have been registered to Orange pay as you go for a minimum of three months.
pay monthlyIn order to have your phone unlocked:
- You must be a current or previous Orange customer.
- The handset to be unlocked must have been registered to Orange for a minimum of three months.
- The IMEI must not be blacklisted (customer services will check this for you).
- Your account balance must be zero; everything needs to be paid up to date.