LineageOSrom.net - Download ROM Lineage OS for Samsung Galaxy S II Celox [LTE] (S2 Korea) based Android Nougat 7.1.1 available. Download the rom first, install/flash it later.
Detail news about this device posted on phonearena.com at August, 2011.
Download Lineage OS ROM Galaxy Celox
Download GApps Nougat 7.1 for Lineagr OS 14.1
TWRP installed on your xiami mi5 (capricorn)
Flash them both in recovery mode the wait till completed.
Wipe Dalvick/Art cache and cache then reboot.