Hey, yes indeed there are reduced prices for under 26s in the majority of cinemas in France and yes there are screenings for many films in VOSTFR (original version with french subtitles). And if you are in Paris I really advise you to go see a film at "Le Grand Rex" in the 2nd arrondissement of Paris, it is the largest cinema in the world but it is above all a mythical place in Paris which has more 90 years old which is even classified as a historical monument.