The exams will take place in a differnt village each time its held.
That Kage will be over the exams or jounin in the village will.
The rule are.

Chunnin exams

NO godmodding
Must post description of the jutsu you use.
If you use a jutsu you must have learnt it and it has to be in your bio.
You can not use any other tech like water walking or tree walking unless you where taught it.
No using weapons your sensei didn't buy you
You charecter must be in the village where its being held
You can not be on a mission while in the exams
Can't sign up till the mission you in is over.

First try is a free go meaning no requirments
Second you must have 5 d-rank missions
2 - crank missions

Only way to pass other then winning the tournament is to do good at the rping and have at least 10 rep points.