The MIUI 9 Global Stable ROM released for Xiaomi Redmi 5 and 5 Plus which was launched at December 10,2017 in China.
The New Global Stable ROMV188.8.131.52.NDAMIEK for Redmi 5 based on Android 7.1 and Global Stable ROMV184.108.40.206.NEGMIEK with Android Nougat 7.1 for Redmi 5 Plus has rolled out to public users. The user needs to check their “Updater App” or visit the download link to get this ROM.
Download link for Redmi 5: http://bigota.d.miui.com/V220.127.116.11.NDAMIEK/miui_HM5Global_V18.104.22.168.NDAMIEK_6f80f691f1_7.1.zip
Download link for Redmi 5 Plus: http://bigota.d.miui.com/V22.214.171.124.NEGMIEK/miui_HM5PlusGlobal_V126.96.36.199.NEGMIEK_a6bb41f592_7.1.zip
Please do backup important data before flashing. If you flash fromStable ROM to Developer, wipe all data, otherwise, it might cause serious incompatible issues like FC, no network etc. In some instance, unlocking of bootloader is required.
For more guidelines visit: MIUI Forum
Source: MIUI Forum