Rooting in Android lollipop 5.1.1, A Sumsung Galaxy SM-J500F Mobile.

How to do rooting in my Android phone? :confused::confused::confused:
Make : SAMSUNG Galaxy J5 - SM-J500F.
OS : ANDROID - LOLLIPOP -V5.1.1
Chip-set : Qualcomm MSM8916 Snapdragon 410.
CPU : Quad-core 1.2 GHz Cortex-A53.
GPU : Adreno 306.
Ram : 1.5 GB.
Internal Memory : 8GB.
And,I am using Avast Anti-virus for my device, is this will affect the operation.
Kindly help me................................................ .............