I can't figure out if this is trolling or cluelessness.
As others said, Rodinal is anything but fine grain. Maybe you can stand it or sit it or something (/snark) and make it work, but I like T-Max developer and I'm sure DD-X would do as well or better, for pushing these films. I love Delta 3200 but sadly have to admit that, for best quality by the usual measures, digital spanks film in very low light. It just does, at least the lowest noise most sensitive digital cameras.
But as Mark says the look is totally different. I've shot D3200 at 3200 but haven't tried 6400. Here's TMZ at 6400 though, printed on RA4 paper with the filtration adjusted to look like the torchlight it was shot under:
SCACOURT by Roger Cole, on Flickr