Bottom of what? See if these help.
Once you have removed the rust, clean and degrease, then freshen up with appliance paint and it will look brand new!
Hi Sannie, Here's a link that may help: https://www.hunker.com/13423497/how-to-remove-rust-from-a-freezer
And, Rust-Oleum makes this appliance paint. It also comes in a spray can.
Unplug the freezer and empty it. Sand the rust off, all over. Paint inside and out with Rustoleum for appliances. Seal it if you wish. After the freezer is totally dry, this is a good time to look at any wiring and hoses and repair as needed. Then plug the freezer in. Let it cool down before adding food unless you have some already frozen to add. Keep your freezer food organized and rotated. If you think it will take a long time to fill the freezer, get empty gallon jugs and fill them with water, then pour out a cup to allow for expansion of water. Put those jugs in the freezer to take up space and keep the food colder. Best wishes to you, 🤟🏻
Sannie,. Try one of the rust remover products. I think Rusteolum has such a product. Call Home Depot and ask for the paint department, and ask them which product is best for rust removal. Restoelum has spray paint you can apply to keep rust from starting. Aloha!