The ROM comes courtesy of XDA Developers' senior member GLokin666, but at this point it's nowhere near stable.
Noteworthy issues are non-functional fingerprint scanners and infrared blasters. The camera on the Redmi Note 4 isn't stable under the Android One ROM as well.
Still if you'd like to get a taste of Android One - follow the source link below.
They don't ask for that much, just a phone number. Others mine for data much much more aggressively.
But we dont have to beg to xiaomi, and give all our personal details to unlock bootloader in A1.