If you want to give a chara: To give a character to the orphanage, you must create the entire bio for them except for the role-playing sample. It is your job to check the role play sample of the people who wish to take your character and see if you think they are good enough to play them. If you do not think they are, make sure to tell them what you think they are doing wrong so they can try again if they wish to.
If you want to take a chara: If you want to take a character from the orphanage, simple do the role-playing sample and see if the creator thinks you are fit enough. If not, you can allways try again.