MIUI 8 is out now and you can download from the mentioned links below. Though it is not a stable ROM but still if you want to experience the new MIUI 8 then you can install it for further use. You will find below the complete guide on how to flash your device.
Please read the guide carefully to learn how to flash the phone properly to prevent malfunctioning of the phone. Otherwise, it is recommended for users to stick to MIUI OTA updates.
New – Manage autostart for system apps (03-28)
Security
New – Manage autostart for system apps (03-28)System
Optimization – System stability improved (03-28)