How to Root Samsung Galaxy S7

This is for the International SM-G930F/FD/X, Korean SM-G930K/L/S, and Canadian SM-G930W8 Exynos models only! Do not flash on S7 edge or Qualcomm models!

WARNING #1: Flashing a custom recovery to your device will trip the Knox warranty bit on your phone. Check with your mobile provider to see if they will still cover warranty on Knox bit triggered devices. If you understand this risk, continue on.
You generally don't have to worry, as it's incredibly hard to brick a Samsung device, and physical damage warranties should be exempt from Knox triggering.

WARNING #2: The Galaxy S7 stock boot image has dm-verity, which prevents you from booting if you swipe to enable system modifications!
SOLUTION: Follow the full rooting steps below, in order, to allow system modifications without the risk of a boot loop!

WHAT IS TWRP?

Team Win Recovery Project is a custom recovery for Android devices.
It allows you to back up and restore your data, flash custom ROMs to your device, repair broken file systems, and root your device.

DOWNLOAD

You can find the device page here:
http://teamw.in/devices/samsunggalaxys7.html

There is a download link there, as well as instructions on how to flash it.

I highly recommend using Odin to flash when possible.
You can find a zip containing Odin as well as Samsung's Mobile drivers here:
https://build.nethunter.com/samsung-tools/

Find Odin Here

FULL STEPS FOR Install Recovery and ROOT

You can follow this video by Max Lee if you'd like: How to Root Galaxy S7 & S7 Edge! [Exynos ONLY]

Otherwise, follow these instructions:
In your ROM, go to Settings -> About device. Tap 7 times on Build number to enable Developer options.

Now go to Settings -> Developer options. (above About device)
You need to enable OEM unlock, otherwise you might end up with boot problems or be unable to flash later on.

Extract Odin_3.12.3.zip to your computer.

Install Samsung Mobile Phone Drivers for Odin to find your device.

Download a .tar image of TWRP for herolte.

Reboot your device into Download mode. To do this, select reboot from the power menu and hold the [Volume Down] + [Home] buttons while your device reboots.
Once you reach the Download mode warning screen, press [Volume Up] to continue.

Open Odin and place that TWRP tar file in the [AP] slot and disable Auto-Reboot, then press [Start].

Hold [Volume Down] + [Home] + [Power] to get out of Download mode and immediately swap [Volume Down] to [Volume Up] (continuing to hold [Home] + [Power]) when the screen blanks.
If you don't see then TWRP boot splash try again from step 6.

At this point, you will reach the screen asking you if you want to allow system modifications.
By swiping right, you will trigger dm-verity, and if you don't follow the next step you will be unable to boot!

If you are going to root your device and follow the rest of these steps, then it is safe to swipe right and enable modifications.

If you want to be rooted with SuperSU:

Download the latest SuperSU by Chainfire.
Without exiting TWRP, transfer the SuperSU zip to your device over MTP* and flash it using [Install] in TWRP.

You will need an external SDcard for this method, if you don't have one you will have to use adb sideload to install SuperSU.

If you only want a bootable system partition:

Download the latest dm-verity and force encryption disabler zip.
Without exiting TWRP, transfer the no-verity-opt-encrypt zip to your device over MTP* and flash it using [Install] in TWRP.

Note: This does not disable the forced encryption on Bxxx firmware, only Axxx firmware due to a change in vold by Samsung.

Go to [Reboot] -> [System].

Wait 2-5 minutes for your device to finish setting itself up.

Source : Xda Developer