It Seems like that u r trying to go to US or DaJiaNa, is it right?
If u are not in US or DaJiaNa yet, it is too early to think about NIW, is it right?
The #1 thing 4 u to do is get the DS-2019 first(it is very easy 4 that professor, because the school can make final dicision, they only need report to CIS, not apply through CIS), then u need try to convence the visa officer to get visa. No one else can give u answer, only the officer can.
Best Wish,