Board Thread:Naruto Discussions/@comment-26273905-20150403160041/@comment-25549954-20150406135016

Yes, Naruto should have all the Tailed Beast chakra to enter that mode, because we know he didn't have all the tailed beast chakra before he underwent that mode, Gyuki was not in him as he was fighting alongside Naruto and Shukaku was trapped in statue so Naruto didn't meet him in subconscious realm as he met all the Jinchuriki along with other tailed beasts, it was only after Obito transferred them along with Yin Kurama did he meet Hagoromo and gained Six Paths Sage Mode. Obito knew what Naruto needed so he stole only those tailed beast chakra from Madara and transferred to Naruto. I think this part is not mentioned in databook.