Download the SuperSU package from the download section.
2.Now transfer the zip files into your device’s internal storage. Place the zip file where you can easily locate it.
3.Now reboot into Custom Recovery (like TWRP). To boot into TWRP, first turn off your device and then press and hold volume down and power keys at the same time.
4.Although this is optional, it is recommended that you perform a nandroid backup. To backup your ROM, tap on backup option in TWRP and select all the partitions: System, Data, Boot, Recovery, EFS and swipe right where appropriate, to backup.
5.Now go back to the TWRP main menu or home screen and tap on the install option. Navigate to the SuperSU file and select it.
6.Swipe the confirmation button to proceed with the installation.
7.Once installed, reboot to system