360 Root app ensures acquiring root rights on Android (1.6 - 5.1.1). Supports more than 9,000 models of smartphones and tablets.

To get root access on a specific Android device, we recommend downloading 360 root.apk file from xda-developers as there are published newest, modified versions for different models of smartphones. 360 Root analogue with limited tools is published on Google Play.
360 Root official version is available at the link below:
How to get root on Android via 360 root
During installation 360 Root requests a lot of permissions to get access to the mobile OS.
During downloading Android will give you a warning about the security threat several times. Therefore, after turning off security settings grant all the permissions and then reboot your phone to activate root access.