Please tell us some basic information before asking for help:
Model Name: Asus x008da zc520tl
Firmware Version: no idea, Indian version
Rooted or not: not rooted
Frequency of Occurrence: always
APP Name & APP Version (If your issue relates to the app): bootloader
In addition to information above, please also provide as much details as you can, e.g., using scenario, what troubleshooting you've already done, screenshot, etc.
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I tried various methods to unlock the bootloader, but no luck to unlock bootloader.
Tried adb via command prompt in windows.