I want to participate in Election. So can anyone explain whole process. And when This event is organized?
This is every year event or specific time duration event ?
When Modarator Election organized?
When I was brand new here, I got absolutely thrashed on Meta.SE for suggesting to have annual elections: Changing the Pro Tem moderators every X months/years, When do Pro Tempore Moderators change?.
So it's unlikely to happen annually, as your question suggests.
Elected diamond moderators remain in power forever (I know that sounds so weird!) unless:
If any of the above three things happens, then a decision will be made about whether or not a replacement is needed, and then usually the community members (like you and me) don't get the chance to decide the election date. Instead it's chosen by SE's community management team, sometimes in consultation with the current diamond moderator team, but not always. If there's extreme backlash from the community about an election date, then the election date might get changed, but it would still be the community management team making the decision.
There's another situation in which an election can happen, and that's if the current team of diamond moderators decides that they want another member. They would then ask the community management team for approval, and then an election would be arranged (but again, you're not likely to know about it).
If you are like me and think this is all weird, perhaps you might like to support the proposal to get more advance notice about election dates.