List installed or running Revits:

pyrevit revits [--installed] [--log=<log_file>]

$ pyrevit revits --installed        # list installed revits
Autodesk Revit 2016 Service Pack 2 | Version: 16.0.490.0 | Language: 1033 | Path: "C:\\Program Files\\Autodesk\\Revit 2016\\"
Autodesk Revit 2018.3 | Version: 18.3.0.81 | Language: 1033 | Path: "C:\\Program Files\\Autodesk\\Revit 2018\\"
Autodesk Revit 2019.1 | Version: 19.1.0.112 | Language: 1033 | Path: "C:\\Program Files\\Autodesk\\Revit 2019\\"

Close all or specific running Revit:

pyrevit revits killall [<revit_year>] [--log=<log_file>]

$ pyrevit revits killall 2018   # close all Revit 2018s