Question: when does naruto learn sage of six paths mode?
Answer: Naruto got his 6 Paths Sage Mode when he was unconscious because the 9 Tailed had been removed from him. In his unconsciousness, Naruto got his Tailed Beast chakra back from Obito with a fraction of the 1, 8 Tailed and the other half of the 9 Tailed so he could be revived.