Bodybuilding competition weights:
Bantamweight 143-1/4 lbs. & under
Lightweight over 143-1/4 lbs. to & including 154-1/4 lbs.
Middleweight over 154-1/4 tbs. up to & including 176-1/4 lbs.
Light-Heavyweight over 176-1/4 lbs. up to & including 198-1/4 lbs.
Heavyweight over 198-1/4 lbs. up to & including 225-1/4 lbs.
Super-Heavyweight over 225-1/4 lbs.
It's like you don't even know the sport? Google bodybuilding competition weight classes. A fitness competition is nothing like a bodybuilding competition--you have to have a special skill (gymnastics for instance)--and go through a routine:
http://www.youtube.com/watch?v=maDqnpCp8QI. There are no mandatory poses. I don't even think they have male fitness competitions unless you think cross-fit competitions count. I think you must be thinking about a figure competition, the type of thing fitness models do. A figure competition can be pretty much the same as a bodybuilding competition except that it focuses upon attractiveness of the person (with face taking the highest priority) and not only about muscular development. Figure competitions are different from bodybuilding in that a 170 lb guy will destroy a 280 lb guy by nature of 280 lbs of muscle being unattractive. In bodybuilding, the opposite would be true. By this nature, a guy who has good muscular development and is at the top of his weight class will destroy a guy at the low end of his weight class in bodybuilding but may lose in a figure competition if he has a less attractive face or aesthetics. Mesoendomorphs have a good chance of winning a bodybuilding competition but almost no chance of winning a figure competition. Fitness model competitors tend to be mesoectos with smaller leg development and a bigger emphasis on having a very strong adonis belt and oblique cut. Beauty pageants, bikini contests, wet t-shirt contests, and fitness model contests are types of figure contests.