Circular brown marks on the face can be due to different skin conditions and the treatment response depends on what the underlying cause is. Some conditions eg. solar lentigines are laser responsive while other types of pigmentation may be less responsive to laser treatment. The background skin type may also influence the types treatment that can be used.
I would advise seeking treatment with a dermatologist to determine the exact cause of the pigmentation so that a proper diagnosis can be made and the appropriate treatment given.