I've downloaded custom models, and whatever else is amusing.
It says in the .txt accompanied in the folder, that the models work as bots, ok.
None of them do.
I was wondering how you are supposed to load a custom bot into a skirmish match? or LAN match?
Open the bot's PK3 (it's a ZIP). There should be a directory botfiles/bots/ containing botname_?.c files (where ? stands for c, i, t and w). If it doesn't have said directory then it isn't a bot.