Rooting using Mac OSX?

[pymason]

Apologies all if this is not a new topic, but I couldn't find it elsewhere. Please redirect me if it is. Daughter just deleted a folder with 2 years of pics and video on her Nexus 7 2013 2nd gen. As it was done outside of the photo app it can't retreive the data from within the app, so I'm looking for a way of retreiving the folder itself. I seem to have found that all the apps that say they can do this need a rooted device to work, so, firstly, does anyone know of a way to root a 2nd gen Nexus 7 2013, now on Android 6.0.1 using Mac OS X? Obviously a free version would be appreciated if at all possible...

Many, many thanks if any of you can help. :-)