if your phone on than you can unlock your bootloader officialy
1. UNLOCKING BOOTLOADER :
- Download the Mi Unlock app to PC, and sign in with your Mi Account;
- Enable Developer Option in your phone by tapping the "Build Number" 7 times
- Go to Developer Options "Settings > Additional Settings > Developer Options
- Enable USB Debugging and OEM Unlocking
- Aslo add account in Mi Unlock Status (Can be found in Developer Options
- Install all the required drivers (adb drivers, vcom drivers etc.) In your PC [I'll link these below]
- Shut down your phone manually, and hold Volume down key and Power button to enter Fastboot mode
- Connect your phone to PC using USB cable and click "Unlock". In Mi Unlock Tool
- You will be given a specific time (168 hours mostly)
- Wait until that and redo Unlock process
- Woah you have Unlocked your device