How to go back to stable rom from beta rom in Redmi Note 4? I have Xiaomi Redmi Note 4 (Snapdragon 625) smartphone. I had updated it to Nougat Developer ROM Version: 7.3.23 (MIUI8) few days ago. But this update led me to some bugs, so now I am deciding to go back to Marshmallow Stable ROM Version: V8.2.2.0.MCFMIDL (MIUI8). I know I can not simply revert back to it via using phone's in-built updater app. So please help me how can I achieve it?

My phone is NOT ROOTED. It's bootloader is LOCKED. How can I once again install stable global ROM which was factory installed by the company when I bought it? I don't want to unlock my phone's bootloader because in order to do so I will have to request to the Xiaomi and I don't know whether it will be accepted or not and who knows how many days I will have to wait for the result.
I would suggest to apply for the unlock. The possibility of not being accepted is rather low. it takes around two days to get accepted but do not forget to go into the developer mode and pair the phone with the account because that needs to be done 3 days prior to attempting an unlock.

Now to the main question. You can download the zip for the version of the ROM you want to go back to and from here
Throw it in the downloaded_rom folder, go in the updater app, click dots on upper right corner, choose update package.

Now... there is a slight possibility that it might not work, failing when it tries to verify the package. If that happens then unlocking the bootloader is your only option.