According to GizmoChina(https://www.gizmochina.com/2017/07/03/xiaomi-reveals-android-n-update-list/), here are the list of Xiaomi phones which will get Android Nougat 7.0 Update. Check out if your phone is in the list.
Xiaomi Redmi 4X, Xiaomi Mi Max, Mi Note 2, Redmi Note 4X, Mi MIX, Mi 5, Mi 5s, and Mi 5s Plus.
Android 7.1 Nougat for Xiaomi Mi 6, Mi Max 2, Mi 5c, and Redmi 4X. Though there is news on Redmi Note 3 and recently launched Redmi note 4.