How may players shall can join on...

[Angemessen]

..... on a RootServer(32GB RAM and 1GB/s 
I want to now your Meaning..

I think there could join about 250 Players, ore more?

[NiLSPACE]

That depends on what they're doing. If everyone is really close to each other it's no problem to have hundreds of players, however, if they are all multiple chunks away from each other the server will have to load allot of chunks.

@Howaner did a test once with ~140 players: https://forum.cuberite.org/thread-1828.html

Also, @xoft did an explanation how memory usage works for Minecraft servers: https://forum.cuberite.org/thread-1888-p...l#pid19670

[ShadowCone]

The limit is definitely rather the cpu than the ram.

My educated guess is, yes.

But do please try it out and tell us afterwards =)