Prakash_Pawan, Help me understand here better , u already got dv -visa and u looking for place to stay, well as it mentions on your dv-program u can stay any where in united states but most likely(unless you change the adress at the entry port) your green card will arrive at the address you have filled out as your sponsor. And applying for ssn must be much easier on that same state. As for you visa getting expired , after u have recieved all the documents form embassy you can always apply for extension to leave nepal , i am not 100% sure but i belive they will extend for a year more easily, if u want to extend for more then that you should be able to convince the counselor in us embassy in nepal. perosnally i would recomend you to be at the adress of your sponsor or nearby for a month or two coz it basically takes 30 days for you to recieve your green card and as for ssn it depends on how soon you apply but you should be recieving that in 30 days time itself if you don;t you can contact the ss dept , as they will tell u to do so . All da best..