Shock Rating
R
There's plenty of violence in Blade Runner: Deckard guns Zhora down in the street, Rachael shoots Leon in the head, Roy crushes Tyrell's head and jams his thumbs into his eyes, Roy drives a nail through his own hand and breaks two of Deckard's fingers… So we're clearly shooting for R territory.
There's also a fair amount of nudity: when Deckard goes into Zhora's dressing room, she appears topless as she gets dressed. Also, in the later releases of the film, more blood is shown, and the scene where Deckard and Rachael first kiss veers more definitely into a sexual encounter.