OP stipulations imply massive rasengan are usable by the avatar, therefor he logically wins given he can utilise ninjutsu whereas Sasuke cannot.
Pretty sure OP said every technique was restricted except Bijuu Dama.
If ninjutsu is purely restricted Naruto still wins. 1 tail blocks PS blade other tails whack it to pieces.
Yes, TBB is ninjutsu and TBB comes in various forms, a Bijuu can form a TBB with its chakra arms similarly to how it forms it with its mouth, so he's still at an advantage.
In strict CQC, Viz has already shown that Naruto's Avatar lost a tail, so Sasuke's PS is stronger than Naruto's Avatar at this point in time. [You must be registered for see links]