We have had official SuperSU for Nougat for a while now, but upon rooting with current builds of SuperSU some users have been experiencing bootloops. This actually happened to me when I rooted Nougat on the Nexus 6P. My phone started to bootloop when the battery hit 20%. That exact bug had been fixed in a later build, but there were still some devices encountering the bootloop. A new update for SuperSU has just been released bringing the version number to 2.79 SR3. The main change here is a bug fix which should prevent even more devices from bootlooping after root. There will be a stable release of SuperSU as soon as it is determined this bug has been squashed for good.
via +Chainfire