Board Thread:Naruto Discussions/@comment-34569788-20180504183427/@comment-32685487-20180504212100

Naruto got Chakra directly from Hagoromo, which is both chakras.. he did not awaken Rinnegan. So its pretty clear you need to have Sharingan first whether it be transplanted or not.. then you get the chakra needed and bam you have Rinnegan.