My sisters parental rights were terminated a few months back to her almost 3 year old son and i just found out?

they live in las vegas nevada and i moved to utah with my 3 sons and my husband. i would like to get custody of my nephew so that he can be with his family and not a foster home. what if he is already adopted? and if not would they let me have him if i go to court and follow all the procedures? would they let him come here to live in utah with us? also couldnt my sister do ANYTHING at all to get her rights reinstated? she is a good person shes just young she was only 16 and a ward of the state herself when she had him and wasnt stable so they took him away and at the time i was only 20 with 2 kids of my own and i figured that she would do whatever necessary to get her son back but now it seems that it is too late for her so i would love to step in and get him???? what do you think? please help thank you