
If you have been able to install the latest and greatest version of Android, Android 6.0 Marshmallow, to your Nexus device you are probably waiting on a root method. A beta method is now available thanks to the work of ChainfireXDA! He recently informed us that he had passed the torch on to another company, but has still been able to crank out a new SuperSU for 6.0! This is labeled as a work in progress, and is not working perfectly on every device.
To root Android 6.0 marshmallow you will have to update to the official build for your device. You will then need to flash the modified boot.img, then you will need to boot into TWRP and flash SuperSu 2.50. It should be noted that this process may wipe data on certain devices. The Nexus 6 and Nexus 9 are the devices that are being reported as having data wiped by this process. Be sure to backup any important information prior to trying out this root method.
via XDA