Your chances are excellent for converting the remaining piece into a growing plant. Stick the stem in soil and it should re-root. I've done this several times when the mother plant was too tall for the space and I topped it.

https://soeasilydistracted.com/backyard/how-to-propagate-hawaiian-ti-plants-cordylines-from-cuttings/

What about this part?

That is the part that goes in the soil. Look at the link.

So the top half with all the leaves should heal from its half broken tap root and be fine?
And the other portion of the broken tap root with sucker roots should grow a new plant?

your words confuse me ....

replant the roots ... they should resprout ...

the top part is most likely too large to root without getting real ugly before that might happen... thats a lot of leaf surface to support ... with no roots... so most likely most of it will wither away before it can generate many roots ...

so lets try searching for propagation videos .. and see if there is anything you can do with the top to make it more friendly to rooting ...: https://duckduckgo.com/?q=Hawaiian+Ti+plant+propagation&t=ffcm&iar=videos&iax=videos&ia=videos

i leave it to you to watch a few of those... and i suspect it will involve rooting small parts of the stem.. after removing a lot of the leaves ... if not all ...

with that big root mass ... you might be surprised how fast the roots can regrow a plant ...

ken

Ken,
The root ball with the leaves and stalks is maybe 2/3 the size of the root ball with the broken tap root.
I’m of little patience and would just go out and buy a new plant. lol So, by next spring, or a whole lot sooner, if I don’t see signs of new growth on either, that’s what will happen. lol

The broken off root part will easily grow a new plant, probably multiple stems to choose from, just put in soil but do not keep too wet.

To save the top, I would just the cut the stem off the top 6-8 inches or so and only leave the top newest leaves. Stick in water or in the soil and it will probably root. You can also root bare cut up pieces of the stem.

This is all pretty easy, you could have a big plant again by the end of the year.

The snapped off roots that I saved, I let dry for the snapped areas to callus. I then trimmed off most of the roots & put the clump in a container of potting mix and then inside of a bag. I guess I made a mistake doing that because the nubs sticking out of the soil got fuzzy. So I guess trying to root from that section is out of the question. 😢
Next, the part with the leaves has gone partially bald from recently dropping its leaves, so I took off the rest, which makes the “trunk” look like damp new wood.
From what I understand in certain videos is to cut the “trunk” into sections & place them upright in water to root.
Here’s to hoping these cut sections take. Wish me luck!