Can Ashura incarnates use eyes of Indra?

[Peculiar Chester]

Yes. If an inferior Senju descendent like Nagato is capable of using the Rinnegan, then it's only natural that a reincarnate of Ashura would also be capable. Additionally, since their chakra would be mixing with the chakra in the eyes, they'd also be able to awaken the Rinnegan that way. We know this because Toneri did essentially the same thing, mixing his Otsutsuki chakra with the chakra in the Hyuuga's "pure" Byakugan to awaken the Tenseigan.

 

[Holy God]

How do? Eyes contain DNA as well. And he is putting them in his own Sockets. Or are you are under the hypothesis, that it has to be ingested in order to mix the DNA? I mean Nagato, Kakashi, AO, and Danzo seem to be able to use other people’s eyes and they aren’t even Ashura/Indra Transmigrants.

Eyes contain DNA, but he's just using them, they aren't merged with him. If someone were to take Yamato's eyes, they wouldn't get the Wood Style. Similarly, Obito took Madara's Rinnegan, but he didn't get Madara's traits, such as unlocking a Rinnegan in the other eye or gaining Six Paths chakra. Yes, all those people you listed can use transplanted eyes, but they still face the exact same limitations I said Hashirama would have.