Root Android 6.0 Marshmallow on Nexus devices

This rooting method uses TWRP recovery for flashing the kernel image files and hence it is important that you download the latest TWRP software (v2.8) for better results.

      
         Downloads

• Nexus 5: ElementalX-N5-6.0-express.zip (9.2 MB)
• Nexus 6: Kernel-shamu-mra58k-color-root.zip (9.7 MB)
• Nexus 9 LTE: ElementalX-N9-4.00.zip (9.0 MB)
• Nexus 9 Wi-Fi: ElementalX-N9-4.00.zip (9.0 MB)
• Nexus 7 2013 WiFi: ElementalX-N7-5.00.zip (12 MB)
• Nexus 7 2013 3G:ElementalX-N7-5.00.zip (12 MB
• Nexus Player (not available yet)
• SuperSU Root package (v2.50 zip)

          Prerequisites

• This tutorial is applicable only for listed Nexus devices: Nexus 5, 6, 7, 9 and Nexus Player
• Your Nexus device must be running Android 6.0 Marshmallow build MRA58K in order to install root via SuperSU

         Steps to root Android 6.0 on Nexus 5, 6, 7, 9 and Nexus Player
         
         Step 1: Download and install TWRP recovery for your Nexus device from below:

• Nexus 5
• Nexus 6
• Nexus 9
• Nexus 7 2013 (WiFi)
• Nexus 7 2013 (3G)

Step 2: Download the custom kernel and SuperSU files from the links provided.

Step 3: Copy and paste both files to your device's storage and remember the location.

Step 4: Boot the device into recovery mode as follows:

1. Turn off the device
2. Press and hold Volume Up, Volume Down and Power buttons together until the screen turns on and then it should boot into fastboot mode.
3. Hit Volume Down twice to enter recovery screen, and then press Power button to select recovery option and boot into recovery mode.

Step 5: Take a backup of important user data and settings on the phone. In TWRP recovery, take a backup of your installed ROM/firmware. Choose Backup and then perform a "Swipe to Back Up" from the bottom of the screen. Wait until backup process completes, as it may take some time.

Step 6: Root Android Marshmallow on your Nexus device:

1. Flash custom kernel first. In the main menu of TWRP recovery, hit Install. Go to the location where you saved the custom kernel file and select it. Then do a 'Swipe to Confirm Flash' from the bottom of the screen to flash the kernel on the device.
2. Repeat the same step to flash SuperSU file like you flashed the custom kernel before. (Do not flash SuperSU before custom kernel.)

Step 7: Return to recovery's Main menu, choose Reboot> System.

Your Nexus device should now restart. After the reboot, you will have root access on it.