Fixed gear bike chain alignment
The pic makes it unclear but I assume flopping the ring in to the middle position has been done and not helped.
First you need to decide whether 52-18 is what you want. It probably isn't. Your answer may inform which route is more economical, since buying a new ring will cost some notable percent of what a new crank would cost. Also, figure out whether the 52 will work in the chainline position you need it to. It very well may not.
If you want to make this crank work, measure your rear chainline and your front chainline. If you have a symmetrical BB spindle, multiply the difference by two and buy a new BB with a spindle that much longer. If asymmetrical, take its measurements and do the chainline/spacer math to arrive at the spindle length you need to simultaneously get the front chainline matched to the rear while also centering the cranks. The usual offset is 3mm but it's not universal.
If this a modern off the shelf track hub, if you drop in any modern track crank with its recommended spindle length it will basically work in terms of chainline. Meaningful exceptions to that are rare. As before, what may not work is frame clearance. You will have to get a sense of that up front before making your other decisions. In some cases that will drive gear size choices.
I'm pretty sure this won't have a French shell, but you should corroborate that before buying things.