It really sounds like he has an ear infection that has spread to his brain(can happen if it goes on long enough) or he has a pituitary tumor(very typical in males that are around a year old).

Either way, he will never be normal again. The infection has gone on long enough for him to become emaciated and dehydrated, and also for him to be rolling. This means his equilibrium is damaged.

What I've done is gotten a can of Hills a/d, mixed it with Ensure or the grocery store brand equivalent(no lactose) and the rats can get the needed calories and liquids from it without wasting energy eating.

I would get some injectable Baytril and give it to him orally(mix it in yogurt or whatever, or just squirt the dose in his mouth). It absorbs faster via the GI tract. You can also put it directly into the affected ear(1 drop) and massage it down in there. I would also get some antifungal ear drops too. My vet usually mixes miconazole, baytril and dexamethasone(steroid) as an ear solution when one of my animals has an ear infection. Beats that infectin to a pulp.

Ear infections in rats need to be caught early(excessive scratching of one ear, bloody discharge, odor from the ear, slight head tilt). Once it gets to where they are spinning, dehydrated and malnourished, then they usually won't be right again.

He does need fluids, so get him to drink whatever you can. Either some fruit flavored pedialite, ensure, watery yogurt, sugar water, things like that. Then get him to the vet as soon as you can. He'll need subcutaneous fluids(under the skin), antibiotics, and hopefully a steroid.

Myco is NOT contagious. AT ALL. Myco DOES NOT cause the infection. Mycoplasma is a bacteria that ALL rats have. It usually does not pose a problem unless the rat is SICK, STRESSED, or a COMBO of the two(just enunciating not yelling). If the rat is sick and stressed(bad choice of cage mates, new environment, poor environment, poor air quality, too drafty/cold, too hot, poor diet)for whatever reason, this will cause the Myco to deplete the immune system to where the rat gets a secondary infection. This secondary infection(respiratory is the usual symptom, but ear infections can also pop up) is what is the killer.

SO! What were those two boys housed in? If they were in a 10 gallon tank, that's why they are sick. I HATE tanks for rats, unless it's ONE very pregnant, or nursing mother with less-than-2-week-old babies. The ammonia builds up and regardless of how much you clean, they are breathing it. Ammonia = lung scarring = constant respiratory distress = slow painful death via asphyxiation.