When trapped by a genjutsu, your mind is teleported to this world. This illiusional world, called Genjutsu Nether, is another dimension where everything is possible, so all jutsus and styles are permitted here. But you must activate or get trapped by a genjutsu to get here.
Every person is given 10000 health. Punches and kicks deals 1000 damage and jutsus deals 2000 damage..
If you want to exit the genjutsu nether, then get killed in the dimension (by losing all 10000 health) or simply cancel the genjutsu with Neutralization (You need to have more chakra than the user to do so. Also, you need to know the jutsu.)