I am doing a 2 camera shot of a person getting tattooed (arm) and want to record the dialog between them (10'x20' room carpet and lots of stuff on the walls)
I have 1 shotgun (Beyer), 1 Octavia MK-012, 2 lavs omni (one wireless), 2 RE50's. Not a real noisy environment but some background noise, not concerned with separation, could be mono. I can boom.
Suggestions?

Wireless lav on each person, and the MK-012 boomed.

We don't know which capsule you have for your Oktava? Omni? Cardioid? Hyper-cardioid?

The dialogue will be quiet, the tattooer and subject sit very close together. I don't think there'll be that much dialogue,
unless you spark them into doing more.

Go along prior and watch some, then you'll get a better idea of what mic or mics to use, and how to record them.

Cheers.

I single overhead cardioid mic like the MK-012 boomed. would probably work good..The shotgun may work too, if it's not in close proximity to the ceiling and/or walls.. IF.. you can get the mics in close enough
A single plant mic could be useful as well Two lavs could be helpful for low level dialog if you have the mics and tracks .DO NOT combine the two lavs to a single track
I would not use a RE50 for this.