If you have access to a computer, professional tools can often remove the lock with a single click: UnlockTool
Ensure Xiaomi USB Drivers and MTK/Qualcomm drivers are installed. poco m6 frp bypass unlock tool
Proceed through the setup until you reach the "Set Screen Lock" page. Re-enable Wi-Fi and attempt to skip or set a new PIN. Accessibility & Google Maps Method by holding both volume buttons. If you have access to a computer, professional