Please explain if it is possible to cure a scar on macula of an eye?

Generally not. A macular scar is the result of some local trauma, infection or blood vessels issue. Most scars destroy the light receptors in that area and light receptors of the retina cannot regenerate. So a cure is very unlikely.
Not likely. The macula is the area of the back of the eye that is responsible for fine focus vision. Once damaged it is not fixible, with few exceptions. If there is scar tissue covering the macula, that can be removed, and some vision improvement may follow. If there is a scar from trauma, infection, macular degeneration or certain inflammation conditions, those ate not "fixable ".