Can a person that becomes paralyzed on right side of body after stroke have mobility again?

A right side paralysis means that the left side of the brain is what was affected. The left side of the brain also continue the major language centers. Is there damage to this person's ability to speak and understand language? A big part of recovery from a stroke is the motivation of the patient to regain lost skills and their ability to understand directions given to them by therapists. Find out all you can about stroke from WebMD or the Mayo Clinic site so that you understand what is going on and what questions to ask.

What do the docs say about rehab?

That would depend upon many things. What part of the brain was affected by the stroke? How much damage was done? How old is the person? What was the person's level of mobility prior to the stroke? How is the person's motivation for regaining strength back? Is the person willing to do PT exercises? How pervasive is the paralysis?

There's just no one answer. I'm sorry.