Board Thread:Theories and Speculation/@comment-38812954-20191014152438/@comment-32685487-20191015040036

No you have to have the dna of the two reincarnates, or if you are an reincarnate already you get the dna of the other reincarnate like Madara and Sasuke did. Zetsu said something that hinted that an Asura reincarnate could awaken the Rinnegan too, so I guess if Hashirama or Naruto was to take Madara or Sasuke's eyes and implant them he would awaken the Rinnegan and/or SPSM.