Really depends on your system, so you should list it.
For windows it'd be: %userprofile%\AppData\Roaming\RenPy
This is where all RenPy based games save files will reside and serves as backup. (so you don't have to worry when switching versions, unless the dev did something that'd break old saves, but I never noticed fessix doing that).
the other location would be, the game\save folder relative to the installation location.
I don't know the locations for linux, mac or android.