There are separate topics for the rushes of each of these shows with recent reports. It makes so sense to discuss these in new topics and will make it confusing for other people to have reports in 2 separate topics, so please go there to read about them. I mean this kindly, and I see that your new here. There is a search function on this board, so you can just search and check if there already is a topic for whatever information you looking for. There mostly is, especially with rush reports :)
I'm linking those you asked about here for you:
Fiddler
Color Purple
Noises Off
One quick thing about Noises Off that I don't think is mentioned in the topic. It's general Roundabout policy that rush tickets are rear mezz only (which is fine, the American Airlines is not that big), and they do not reserve tickets for rush. If the show is (almost) sold out for a particular performance, there will not be a rush at all. Typically they put a sign the evening before though, so at least you know when you get to the theater & don't have to wait until the BO opens to find out (that's what the did for On The 20th, I think). They also have a student rush that's 50% whatever they have left 30 min before curtain. With some luck you can get a box seat for $30 that way, otherwise it's pretty expensive for a rush... GR is 2 per person, SR is one per student ID and they check and are strict about it.