Unlock SIM for iOS 8.4.1

My uncle who lives abroad gave his iPhone 4s which locked to Drei. in Austria. I can’t use and I can’t even activate it without valid sim card. How to unlock it if it’s possible ? Thank you
Answer #1
You have to pay for the unlock. There are also free options that you can try but they require experience, knowledge and having the risk of bricking the phone.
Answer #2
It’s not worth it, the phone is too outdated.
Answer #3
gevey unlock sim.