There is no such thing as nursing school that is 100 percent online. They will be a lot of things that you need to do in person (for example, how are you going to learn how to give an injection because you will have to demonstrate it or practice it.)
Furthermore if you go to a nursing school that is not based in United States, you may not be able to take your license examination at all and this mean you will have wasted a lot of time and money.
http://www.rn.ca.gov/careers/steps.shtml This is for Californians, but it applies to other states, as well.