thread moved to international forum as you have other requirements that must be met since you graduated from overseas. even with the green card, you still need to go thru the same process that foreign nurses need to do. illinois requires that you go thru the ces process available thru cgfns, they will not permit you to sit for the nclex exam without having that done.
immigration and licensure issues are completely separate. you will need to apply for licensure as an rn and get permission to sit for the nclex-rn exam, you do not just apply for that exam.
please take the time to read the stickies on the international forum for information that you will need, in particular the one called the "primer."
and welcome to the us and allnurses.com.