See here: http://www.navy-prt.com/malestandard/20-24.html
Although you should certainly attempt to achieve the results nuensis mentions I would think a score of at least "excellent" would be needed for an NROTC applicant in this day and age. Of course the closer you can get to max the better, and you should always be working to achieve max.
Hey Kinnem, do you know the date on these standards? DS has been using the 2011 standards on his school NROTC site and these are "easier" than the ones he's working towards...in the run especially. He'd prefer your standards to the ones he's been working with!