How to unscrew the wheel nut if it is ripped off?
if we are talking about a nut, not a bolt (what kind of machine is this? Okushka?), then the "first line" of solving the problem is a chisel. In this case, it is recommended to water the nut abundantly with WD4. If the chisel does not help, then on the tow truck to the car service. There, a lever will be welded to the nut (for example, a long water pipe) and the governor will be unscrewed, but expensive ...
On the road, there is only one way out - take a good chisel and chop the nut, holding it with an open-end wrench so that it does not spin, if you can rest the key against something, even on the ground. rarely does anyone carry it, but you can always borrow it from passing truckers, but take a good sledgehammer from them, this will speed things up a lot! Perhaps, removing the nut, you will see that the thread on the hairpin is torn off and you cannot tighten a new nut - it's okay, you can safely get there home and without one nut, then repair everything!
I understand that the nut is gnawed, the cylinder key turns on it! Then try to put a washer or a strip of metal on the edge of the key so that the key sits on the nut with an interference fit (drive the key onto the nut) or drive up to the craftsmen in the garages.