In order to fulfill the basic functions of our service, the user hereby agrees to allow Xiaomi to collect, process and use personal information which shall include but not be limited to written threads, pictures, comments, replies in the Mi Community, and relevant data types listed in Xiaomi's Private Policy. By selecting "Agree", you agree to Xiaomi's Private Policy and Content Policy .
The bootloader is locked. So you cant use recovery mode of this device to install firmware or to reset the device. You need to unlock the bootloader by taking the permission from mi.com. You need to submit the request to unlock the bootloader giving valid reason & of granted .. you can unlock the bootloader by the software 'mi unlock'. This software will ask you the mi login id & will check if the permission to unlock the bootloader given or not. Then it will proceed further.
But Unlocking bootloader will make your device unsafe as the security features like find my phone etc. will be disabled.. & it will not be able to accept the future updates.
But its to tell you that You can lock the bootloader again.
If you're updating from Stable to Developer ROM. It is better to flash with Fastboot ROM. Using Recovery ROM for moving from Stable to Developer is not advised.
This is what you can do, backup your data locally; flash with Fastboot ROM and restore your data.