This information is for Macintosh users. The ThemeStudio was created at a time when Apple included Java by default. As time moved on, Java was removed from the default install of macOS.
There is no harm in leaving the Legacy Java 6 install on your Macintosh. In fact, if you're trying to get an older version of the Theme Studio running then you may need to install it. You can find it here.http://support.apple.com/kb/dl1572