First, go to the official guide and follow the instructions, pretending you want to setup a 3on3 CTF server. Now you have to do these things:
- create a copy of the ladder_3on3ctf.cfg and name it ladder_5on5ctf.cfg
- open ladder_5on5ctf.cfg in a text editor, change the line set g_maxplayers 6 to set g_maxplayers 10
- Make sure that your maxplayers setting is set to >= 10
- Optional: in your server config (the one that sets up the hostname etc), add: alias 5on5ctf "exec ladder_5on5ctf.cfg; endmatch" and also add addvote 5on5ctf somewhere
No support available.