MIUI 9 was announced along with the Xiaomi Mi 5X last week and its official rollout is starting in a week for china. The first two phones to get it are the Xiaomi Mi 6 and the Xiaomi Redmi Note 4X are in the first dipatch, mobile released recently in 2017.
Second dispatch will start on August 25, Two weeks after the first dispatch 12 other phones will get MIUI 9. They are the Mi Mix, the Mi Note 2, the Mi 5, the Mi 5s, the Mi 5s Plus, the Mi 5c, the Mi Max and its newer sibling the Mi Max 2, the Mi 4s, the Mi 4c and the Redmi 4X.
Third dispatch will be around september and it will include some entry level devices from a few years back – Redmi 2A and Redmi 1/1S.
The new MIUI 9 brings Smart app launcher, Image search, and Smart assistant. It also has a particular CPU acceleration mode and better haptic feedback. Xiaomi promised to deliver the Global version soon.