I have two method to root myphone Rio fun V2 android 4.4.2 kitkat. Method 1 using kingroot and method 2 it need CTR.(carliv toch recovery) or any custom recovery like twrp,cwm,philz touch etc,
Note: Rooting can void your warranty!
I am not resposible for any damage or soft/hard brick will happened to your device!
This method need to be rooted.
1. Go to Recovery
2. Mount System and Mount data
3. Install update via zip SuperSu2.01.zip
4. Reboot and wait you notice your android is upgrading..
5.Check if you install SuperSU