How to root in MIUI 8 and probably MIUI 7 and MIUI 6. Well I just tried it in my own Mi4c with xiaomi.eu_multi_MI4c_V8.0.4.0.LXKCNDG_v8-5.1 rom.
Step 2. Move that file to your phone
Step 3. Install via TWRP.
Done
Just wrote it so that I don't forgot how to. lel