I don't see how we can be calling here because the relative strength of our hand is just really, really bad. You basically only beat a bluff facing a shove here, so you need at least some sort of read to assume this villain will shove over you with a busted draw or a really shitty played mid pair. I don't see the benefit in betting the river here TBH other than as a blocking bet. I don't think a weaker pair is ever raising and if you bet + get raised you're just guessing whether or not your being bluffed back at because you have no reads.

Therefore: b/f or c/c > b/c.

I play full ring mostly and a little 6-max so I'm not sure I can say this about 6-max but *in general* (disregarding specific player reads) I've noticed that at low stakes, most people don't get too out of line when they raise you on the river. Pretty much no one at this level understands the concept of raising for thin-value (A raise is normally a pure bluff or the nuts), so your either WA/WB, and I'm looking more towards the side of way behind because we don't have any information on this players postlfop tendencies.