It realy depends alot on how quick you loose the weight before hand that they want you to loose and how dedicated you are. I think I was one of the quicker ones, I went to oreintation and had surger 2 months later. but I really busted my butt. I know some people take years some a few months.
Good luck I was 247 at orientation and am 164 now (2yrs later) still have a little to loose but I feel pretty great