There are advanced clinical treatments such as chemical peels, skin whitening treatments and laser therapies available for all problems that you mentioned, sometimes just one treatment can solve multiple skin issues. But facial plastic surgery would be a different thing altogether, it will either be reconstructive type which would be concerned with changing the appearance of certain facial features depending on their shape or color (and not merely getting rid of skin problems), or it would be cosmetic type which would be same as enhancing features but on an extremely smaller scale, they would be less invasive surgeries such as correcting fine lines, lifting face, or botox. If only darkness, uneven skin tone and pimples are a problem, then plastic surgery isn't needed. Still, just so you can gain additional information, here is a page which links to relevant hospitals - Best Cosmetic And Plastic Surgery Hospitals in India, but before you make a trip to any of these hospitals, it's advisable that you first seek consultation from specialists - Dermatologists in India. Let us know if our assistance is needed anywhere.