Complex sentence: The CNIL is composed of 17 members from various government entities, 4 of whom are members of the French parliament ("Assemblée nationale " and"Sénat"); 12 of these members are elected by their representative organisations in the CNIL.
Split into simpler sentences: The CNIL is composed of seventeen members from various government entities, four of whom are members of the French parliament ("Assemblée nationale " and"Sénat"). Twelve of these members are elected by their representative organisations in the CNIL.