As far as I know once your OPT expires you have 60 days to leave the country but don't think you can work during that time. However if you join school for bachelors then you will be able to use OPT again once you get done. I don't think you can work as RN outside unless you have EAD ie workpermit and you can only work for 20 hrs. OR get CPT which is like taking a class which allows you to work as RN for 40 hrs. I will be in the same situation as you are next year 09. So, I am planning to pursue Masters just to be on safe side. Yeah thats all I know!!