No it's not real. There are all kinds of power groups in the world but the world is far too big a place for something like that to have any kind of power. Many leaders have trouble just keeping a handle on their own country.
For instance the G8 and G20 are examples of powerful people meeting to sort out common problems.
But there are people who actually make a living convincing the less educated and not too bright that such organizations as the Illuminati exist.