Thanks Harris and other guys for good suggestions... my mentor pays me for the assistanceship... I believe I dont need to join community college or kaplan. Only thing is my mentor does not know the immigration laws. I have chances to go to better universities but I am worried that if I move, It may take 5 more years to do PhD which I dont like to do..... Now I can clarify the situation. He even dont know the OPT . Thanks guys