Is there a way for Naruto to get the Rinnegan?
I guess, if you combine Ashura's and Indra's chakra, you will obtain the ultimate dojutsu (Rinnegan). Since Naruto is a rebirth of Ashura and if he can implant Sasuke's chakra (since  Sasuke is a rebirth of Indra), Naruto probably will obtain the rinnegan.