OK buts it depends on wat kind of working visa and weather ur bro in law has family in us or not and also depends on the yearly income of ur bro in  law and credit history. since ur bro in law in USA first u should talk to him about all above things and if the income exceed the minimum requirement of university and if he has sufficient money required by college in ur bro in laws US bank then there is a chance u can try that from ur bro in laws but see here is the thing doing it from US is more hectic than from nepal because if the person who is in us is sponsoring you embassy can look after his background deeply and any kind of issue could harm you but if u did from nepal they will not have acess over background check of ur parents so its lot easier to do from nepal and it worked for me few years ago coz mine is same case as urs. anyways when u will get here ur bro in law can help u as much as he can....this is just my thought and experience so BEST OF LUCK!!!!!