On a terminal type:
Another option is to look at the /etc/apt/sources.list file
deb http://packages.bosslinux.in/boss eduboss main contrib non-free
You’ll see a line like the one above, look for the word immediately after the URL, here its eduboss, this indicates the version of BOSS GNU/Linux running on the system. The lsb-version command provides more accurate information. The lsb-release command should work on most distros(as long as they are LSB compliant).