error 86006

Να υποθέσω ότι τα έχεις κάνει αυτά - - - - > Πάτα επτά φορές στην έκδοση miui να ενεργοποιηθεί και μια που θα είσαι εκεί κάνε και enable usb debbuging και enable oem unlock. Ρυθμίσεις (Settings) => Πρόσθετες Ρυθμίσεις (Additional Settings) => Επιλ. για προγραμματιστές (Developer Options) => Κατάσταση ξεκλειδώματος Mi (Mi Unlock Status) Κάνεις add το mi account εκεί που λέει unlock status (πρέπει να είναι κάτω από το OEM unlock)

@dimmyf αν δεν τα καταφερες ακομα, κανε τα παρακατω βηματα
Note: I have Mi Unlock tool version 2.3.803.10 (latest as of now). I'm on Windows 10 x64 build 15063.

1. Extract the zipped archive of MI Unlock tool to the root of your systemdrive, like C:\any_folder. I extracted it to C:\unlock, so the path of the tool's executable became "C:\unlock\miflash_unlock.exe"

2. Run MiUsbDriver.exe from the folder with as administrator and click "Install". Make sure it says "Driver installed" after that. If it already says that, hit install again just to make sure. Click "Retesting" to see if it remains the same. Close the program after.

3. Put your device into fastboot mode (make sure to turn on USBdebugging and OEM unlocking in the developer options), and connect it through USB 2.0 port. (I don't know if 2.0/3.0 makes a difference but if you have 2.0 available, use it).

4. Go to devicemanager. Expand "AndroidPhone", right click "Android Bootloader Interface" and click properties. Click on "Driver" tab. See if the driver provider is "Xiaomi Technology, Inc.", driver date is "11/3/2016", and driver version is "16.0.0.0".
IF it's not, then close the properties window, right click android bootloader interface and click "Update driver". Click "Browse my computer for driver..." then "Let me pick from a list ...". Uncheck "Show compatible hardware", click "Xiaomi Technology, Inc." from the left side, then "Android Bootloader Interface" from the right and click next. After it's installed, check the properties to make sure it says what I mentioned above.

5. Go to unlock tool folder. Go to driver\win10 folder, right click android_winusb.inf and click install. You'll get operation completed successfully message.

6. Go back to unlock folder and run the tool as administrator. Now before clicking agree, click on the settings gear on the top right corner. Make sure MIUsbDriver says "Already installed". This is really important. Otherwise IT WON'T WORK. If it doesn't say that check previous steps and make sure your didn't miss any.

Πρωτα δοκιμασε να βαλεις τον φακελο miunlock tools στο δισκο C και δοκιμασε αν το βλεπει αν οχι κανεις και τα αλλα βηματα