Rooting your Samsung Galaxy S7 is now possible by jcadduono - XDA Senior Member.
He made a thread on xda forums about installing TWRP and Rooting Process.
In this article We will show you how to Install TWRP and Rooting for Samsung Galaxy S7 Device.
How to Install TWRP :
First download odin, drivers and Recovery img from below
Install Drivers on your computer
Extract odin and Place it on your desktop
Copy twrp on odin folder
Now Enable OEM Unlock on Developer options in your galaxy S7
Reboot your device into download mode.
Connect your device to computer and open odin software.
Add recovery file on [AP] in Odin Software
Click on start..
Now, you have successfully flashed twrp on your samsung galaxy s7.
How to root :
Copy it to your SD Card
Now reboot your device into recovery mode.
Click on install option and select SuperSU
Wait for the flashing finishes..
Now, you have successfully rooted your Samsung Galaxy S7.