Pausing is not possible in our smaller League of Legends tournaments - with team sizes of 1, 2 or 3 players. (1v1, 2v2 & 3v3).
We do allow pausing in all of our 5v5 tournaments, however.
A team may then pause the game if they have a legitimate reason to. You must quickly communicate to the opposing team what the nature of the issue is. You must not unpause the match until both teams have confirmed they are ready.
Each team may only pause the match for a maximum of 15 minutes each.
Valid reasons for pause:
A player experiences an unintentional disconnect
A player experiences a software or hardware malfunction
A player experiences a physical interference (broken table or chair etc)
If you are participating in a 5v5 tournament you will be able to find these rules in the Rules tab located the upper menu bar of the tournament you have joined.