$nick(#,0) will return all nicks in the channel.
This is all the information you need to know to make a script to timeout all / random.

Assuming you want a remote text event, here's a randomp picker for you.
on *:text:!random:#: { 
var %nicks $nick(#,0)
msg # There are %nicks users in this channel right now.
var %rng $rand(1,%nicks)
var %nick $nick(#,%rng)
msg # The user I randomly selected is %nick $+ .

Let me know if you need further explanations. Try to use the help files before asking for help though. Here are some useful reads.

/help variables
/help on text
/help if then else
/help <insert random identifier here>

Nillens @ irc.twitch.tv
Nillen @ irc.rizon.net