Try a different USB port (USB 2.0 is often more stable than 3.0 for Fastboot). Ensure you have installed the drivers from the tool's settings menu.
You must link your Mi Account to your phone. Go to Settings > Additional Settings > Developer Options > Mi Unlock Status and tap "Add account and device" . mi unlock 6.5.406
Plug your phone into the PC. The tool should display "Phone connected" . Try a different USB port (USB 2
The is a stable, legacy version of Xiaomi’s official software designed to unlock the bootloaders of Xiaomi, Redmi, and POCO devices . While newer versions like 7.6.727.43 are available, version 6.5.406 remains a popular choice for users working with older MIUI versions or those who find it more stable on certain Windows environments. Go to Settings > Additional Settings > Developer