Q.My 3 Ft Corallant Rotted Out At The Bottom But Still Has New Growth At The Top. How Should I Cut And Replant?
Is it possible to cut the bottom that is rotted, let dry and repot?

Certified GKH Gardening Expert
Unfortunately, your photo did not come through. I have never encountered a plant by that name. Perhaps, you meant Cordyline?
It won't be possible to save the rotten bottom. You may, actually, have better luck saving the top. You will still have to fight an infection if it roots, but it gives you the chance to save the plant.
These articles will help you:
https://www.gardeningknowhow.com/garden-how-to/projects/rooting-plant-cuttings.htm
https://www.gardeningknowhow.com/garden-how-to/propagation/cuttings/root-stimulating-hormone.htm
https://www.gardeningknowhow.com/garden-how-to/propagation/cuttings/honey-root-hormone.htm
Here is an article that will help you to care for Cordyline: https://www.gardeningknowhow.com/houseplants/ti-plant/cordyline-plant-varieties.htm