Naruto will get the rinnegan for sure sauske has a lesser chance of gaining one.
Actually Sasuke has the greater chance. The formula for rinnegan is EMS + Senju (or Uzumaki) DNA. Sasuke already has the 1st requirement and he can get the 2nd one from a variety of people. Those people include: Naruto, Tsunade, Yamato, Karin, any Zetsus that he could find, Orochimaru (since he has a Zetsu body now), Orochimaru's lab, Hashirama's living clone, and Obito. This list does not even include the edo tensei Senjus that are there or Madara's Senju DNA. The only EMS eyes that Naruto has access to are Sasuke's (and he would have to fight Sasuke to take his eyes). The only other chance for Naruto to get rinnegan is for my (and a bunch of other people's) theory to be correct. That theory is that the bijuu chakaras inside Naruto will give him rinnegan.