I own a 2015 Toyota Limited Hybrid Highlander. Does it have a AWDi system?
I would imagine on the back of the vehicle there will be a label (AWD ) and if it is there then you have all wheel drive. Of course you could look in your manual or call the local dealer.
Your Highlander Hybrid has AWD, all Highlander Hybrids since 2008 have AWD.
If you look between the rear wheels you should see axle shafts and an electric motor.