How to remove oppo a6 FRB

Do you mean FRP? As in Factory Reset Protection? The thing that keeps you from using a phone that you don't have the Google account information for, even if you do a factory reset?

If that's what you're looking for, I'm afraid you're in the wrong place. iFixit concentrates on hardware repairs and doesn't have a focus on software issues like yours. In addition, even if we wanted to help, the moral implications of helping someone defeat security measures meant to keep a stolen phone from being used would keep us from trying to assist you defeat the FRP feature. I'm not accusing you of having a stolen phone, but we have no way to verify whether the phone is yours or not.