If you are looking for safest way to root your one plus 3 on latest android OS , follow the step by step guide provided in the video . First make sure you download series of the tool provided in the link below
OnePlus USB Drivers – http://bit.ly/1TbsPG2
AndroidSDKSlim – http://bit.ly/1SCu3du
SuperSU – http://bit.ly/1YyfIRW
TWRP – http://bit.ly/28MdSRU
Make sure developer mode and usb debugging is turn on. This can be done by going to setting > about section > build number and tapping it for 5 times. After that go to developer option and turn usb debugging on. After doing steps follow the video below to root your one plus 3
If you have any problem rooting your one plus 3 or in case if u didn’t understand the steps provided in the video , comment below and I’ll try to help.