It's a tiny cubbyhole at the tippy-top of one of the coolest clubs in town. And it's exclusive. Not "exclusive" like other nightspots, where anyone with $300 to plunk down for a bottle of scotch is admitted. Entry into Level 6 is by invitation only. And isn't that what a VIP room is really about? Level 6 also has its own bathrooms -- another distinction it claims -- though it's a dubious one: They're rarely in service.