Could Kakashi obtain the rinnegan because he has uchiha dna in him and its possible that He could get some senju dna or maybe Kakashi is harumos reincarnation
If Obito is truely dead, Kakashi can go and take the two sharingan for himself. I believe this is why Kishi is keeping Obito if he is truly dead. If not then he might wake up!
As for the rennigan, Kaguya has already used it in her transformation.
Could Kakashi obtain the rinnegan because he has uchiha dna in him and its possible that He could get some senju dna or maybe Kakashi is harumos reincarnation