it is possible to adapt the "Idle connection timeout" on MAC OS? If yes. Please describe me how I can do that?
Do you mean on an SSH session? you don't make it clear at all what you're actually doing, or on what version of OSX.
If so just edit these values in /etc/sshd_config and restart sshd, this'll change it for everyone.
If you meant something else you're going to have to learn to be much clearer.