An article on the crowd reaction in the movie theater watching the end of Return Of The Jedi back in 1983:
“Star Wars fans scream for Darth Vader twist in 1983 reaction video” at the Digital Fix
The video:
“Darth Vader’s Redemption - Cinema Reaction (1983)”
https://www.youtube.com/watch?v=MhHn6oD-B7M : a 2 minute video at Clavis YouTube channel.
I found it interesting to see, but if I were in the movie theater I would have gone back to a later viewing to try and watch the ending in more quiet surroundings!