I haven’t been through this with a rabbit, but I have with a dog and humans.
The severity of this depends on how big part of the disc that’s protruding and what structures it is putting pressure on. 6 days on NSAIDs is a very short time. I think you will need to keep her on NSAIDs for quite some time, but after 1-2 weeks it might be possible to lower the dose. (It’s a good idea to also give Pepcid (famotidine), because meloxicam is hard on the stomach lining. You could mention this to your vet, Pepcid is a cheap drug with few side effects).
Herniated discs do as a rule heal, but it takes time. It can be several months, sometimes even longer, before the animal regains full sensation in and control of the legs/leg. Obviously young-ish and otherwise health animals heal quicker than old or poorly rabbits.
She shouldnt jump at all tbh, especially not down from things. The impact on the vertebrae when landing can undo a lot of the healing. It’s an excellent idea with the ramps! Moderate exercise is good and necessary, it helps healing because it increases the circulation in the small, small vessels that supply the bone, cartilage and nervous tissue with nutrients and oxygen. It’s obv aso important to maintain healthy muscles.
It sounds good that you’ve started treating for ec while you are waiting for the test results. Hind end weakness is (as you know) often seen with ec. The most common treatment is Panacur for 28 days. Panacur is a very slow-acting drug, so it often takes time before you see improvement.