That's ugly all right. But if you cut it down that low it very well might not sprout from the scion. If you are a good grafter then cut scion wood from the top and use it the graft down low.

Without protection from deer you might as well leave it alone. The new low top will just be damaged again. The current top can produce fruit above deer height. It will need some pruning and continue support but is an option.

Most of the fruit trees will be fenced in. But this tree will be probably left out. Deer would not bother the tree after it is staked.

If I re-train the tree, it will be protected with things like drain pipe or wire cage.

But I do not know if the grafted wood would send out new growth above the graft union.

If cut down to near the graft union it will likely not sprout from the scion. It's more likely to sprout from the rootstock.

The trunk is good at about 3" above the bud union. Or I can try to cut it to 5-6" about the bud union. I just do not see any bud eyes anywhere on the main trunk.

Please, that tree is garbage, cut it down and begin again. Apples and pears can be rebuilt, but to a certain degree with peaches you only get one shot and it's been spent, unless you can live with scaffolds starting where the one now exists and a very crooked trunk.

A new tree, even a skinny whip, will provide you with full crops much sooner anyway. If you have a thing for saving dying trees, strip off the flowers, juice it with some kind of nitrogen (several aps from mid-spring into mid-summer), keep the soil moist and all weeds and grass away from at least a 3' diameter ring from the trunk. Before you think of training it you need to restore some vigor.

I have had young new trees send to me that didn't sprout any new limbs when cut down. I would say chances are zero to about none it will sprout any branches low.

The tree had two more scaffolds before deer had some interest in the tree. Then the tree just has one scaffold like it is now. Deer just leaves it alone now. The tree was also slanted before it was staked.

We'll probably just cut it down to where the trunk is not damaged. It new shoot comes up, great. If not, we'll just replace it. We have 3 more peach trees close by and they are in good shape.

I think the damage extends lower than you realize.

A vigorous replacement will come into production sooner than will this poor thing.

Hman is right. That tree is more trouble than it's worth.
Get rid if it and plant a new whip, but you sure better protect it from the deer or you'll be right back where you started.