why i cant get in to the dalek mod server (public)?

are you using the correct version of the Dalek Mod ?

yes 41.1 when i try to get in its show me "failed to connect to the server"

It is most likely  your internet then or the server is lagging too much for access

https://swdteam.co.uk/forum?p=thread&tid=280

This thread did not have to be made. 

Check the link above