Looking for older Q&As is definitely good, but the one @abrzozowski linked is a bit old and the answer leaves an important bit of information implied: yes, you can install multiple ROS versions on a single OS, but, there need to be multiple ROS releases for that OS available.
Kinetic is available for Ubuntu Wily and Xenial (REP-3 - Platforms by Distribution - Kinetic Kame).
Indigo is available for Ubuntu Saucy & Trusty (REP-3 - Platforms by Distribution - Indigo Igloo).
There is no release of ROS Indigo for any OS that supports ROS Kinetic, so @Chucolate will either have to downgrade from Ubuntu Xenial (16.04) to Ubuntu Trusty (14.04), or attempt a source build of ROS Indigo on Ubuntu Xenial.