I familiar with that area. It is the less fertile side of the Catskills, so the fishing isn't generally as good as the Delaware/Sullivan Co side. But on the other hand it draws less people. Being less popular there are no good special regs areas, so trout fishing is closed 10/15 to 4/1, the general closed season for New York. Plus those mountain freestones are iced in now. Wouldn't really fish there much until end of April. The stream closest to Cairo is Catskill Ck. I like the area around Oak Hill; up by Preston Hollow there are tiny wild rainbows. The NYS public fishing maps of the area are here. https://www.dec.ny.gov/outdoor/44854.html
From Cairo can head over the mountain to Windham and the Batavia Kill drainage. The valley soils are a red clay so much of the stream in silted, but locals have a few honey holes if you can find them. Hike to the upstream tribs in state forest land for little brookies. Drainage really got hammered in the last couple of hurricanes.
The next valley south is the Schoharie Valley, which has the Hunter Mtn ski area. A less fertile stocked brown stream, tribs off the mountains have brookies. Further down just above the reservoir is where Art Flick had his place.
For crazy fishing can follow the Kaaterskill or Plattekill as they tumble off the east face of the Catskill escarpment. Tough walking along steep streams, but a different experience. Near roads plenty of swimmers, but they don't walk far.
Further south the Rondout Ck valley cuts through some limestone and is a good fishery not visited much by visiting anglers. Famous Blue Hole is now public up in the mountains, but largely ruined by over use from swimmers. Swimmers are a big issue in that side of the Catskills and have caused plenty of good holes on private land to be posted and good holes on the public land to be trashed. ie, the good hole on Catskill Ck at Oak Hill was a swimming hole for as long as anyone's memory, but got trashed in recent years from over use. Fortunately, the public access was by Public Fishing Rights (PFR) which give fishermen access, but don't allow other activities.
There is decent and less crowded fishing on that side of the Catskills and it is worth a cast if you are in the area, but I wouldn't travel far just to fish there. Plus, the fish will be lethargic until late April/early May.