How to report someone on tribunal or he is automatic going on tribual when he is reported in game ?

Thank you

When you report someone using the report function after a game,the case goes to the Tribunal automatically(usually after a fair amount of time,ie 2 weeks or so)
"Unskilled player" reports don't show up on the Tribunal though,they are just there for "improving matchmaking reasons",according to Riot.
So yes,when you report someone in game,the Tribunal handles it.

If you report someone (for example, Offensive Language), it'll take around 2 weeks and it ends up in the Tribunal.
A lv. 30 Summoner then decides on if s/he is worthy of being punished or should be pardoned.
Just because you're insulted doesn't mean that everyone else is; it varies and some people that's reported tends to be reported by those that SHOULD have been reported.

Hmm, I thought they go to the Tribunal faster, but actually reaching a verdict takes more time. Might be wrong tho.