In pokemon ranger: shadows of almia, when you finish operation brighton( the final
mission/ gets you to ranger rank 10), you will have access to the capture arena, and to
get to it, take a boat ride or use staraptor's ability to get to haruba village,and go to
the second port(the one where you first get to haruba village) and take a ride on the
wailord that should be there and you should end up at the capture arena.
in the capture arena, there are 4 floors to complete, similar to the elite 4 of pokemon
ranger.
there is a save machine and styler recharger on every floor ( except the last floor) and
you can only tak your current partner pokemon with you.
each floor has a different number of rooms with a different number of pokemon to capture
to clear the room.
also, you are not  allowed to take pokemon out their room to use in other rooms.
in each room, there are a different number of pods that lead to a small room, each with a
pokemon in them, and all pokemon per room must be cleared to move on to the boss of the
room.
the room number, number of pokemon in each room and the boss are stated, in that order.
1st floor [5 rooms] )1,1,croagunk. 2,1,spiritomb. 3,2, lucario. 4,2, heatran.
5,3,cresselia.
2nd floor [4 rooms] )1,4,gliscor,yanmega. 2,4,mamoswine,tangrowth,rhyperior. 3,5,glaceon,
leafeon, umbreon. 3,5, weavile(4), drapion.
3rd floor [2 rooms] ) no pods in this floor, 1, magmortar, electivire. 2,empoleon,
infernape, torterra.
4th floor [rooftop] ) this is the final floor in the capture arena. you have capture a
salamence, flygon and a chaizard all at the same time, and there are no other pokemon that
can be caprued there so you can't use pokeassists there, apart from your partner pokemon.

hope this make sense