What sort of mods do you usually use or enjoy? That way I can recommend mods that suit what your after rather than a bunch of random ones. Most regular mods like Roughly Enough Items or Fabric API update regularly and the odd new ones appear every snapshot or so (and while some on past snapshots work on 20w19a not all will either so best to stick with the same snapshot usually).
For Claim/Towny/Permission like mods the last I remember are these for 1.14 and 1.15 versions (Forge & Fabric) but 1.16 doesn't have one yet:
Other than these I've only come across inventory security mods more than block prohibiting or Towny type I think (when listing mods in the forums, spotlighting mods on Youtube or briefly looking past for other mods).
I'd also recommend datapacks if the mod options don't work out and these could work on 1.16 snapshots as I've come across a few datapacks on 1.15 work but I can't say for these ones as I've not used them, but they are worth a try: https://www.planetminecraft.com/data-packs/tag/claim/
In terms of when past Claim mods for Fabric came out, the 1.15.2 one Get Off My Lawn took a while to come out, but the 1.14 one ClaimChunk was near 1.14's release from what I remember so depends on the devs and what mods they come up with at certain times/is requested in their Discord I guess while Forge has much more options updated often.
I'll keep my eye out for one and pm you but for now this is all I'm aware of. But in short best to go with 1.15.2 Forge/Fabric but if you want to try 20w19a I'd say experiment first not go expecting 1.16 snapshot to be stable (even though I've not had mod issues compared to 1.14 or 1.15 era) or fully Towny accessible just yet. 1.16 should be finishing up at some point in the next few weeks I think with how there is mostly bug fixes and minor additions.