Counter-Strike 1.6 LAN is simply a no-steam version. You can only play on LAN with friends (and no trough internet).
Report a problem or an outdated installer
Report any problem you might encounter with the installer. You can
also report here outdated installers. If you have problems
installing or running the game, don't forget to specify your
distribution, (+ version and architecture), your graphics chipset
model and the driver used.