Tooth problem. Tried so many medicines.

The most common reason for such Yellow or slightly brownish lines on the teeth is fluorosis caused by high fluoride content of the underground drinking water specially in North India. It is basically a Cosmetic deformity and not a disease in itself. There is no medication which is going to treat or cure or even lighten this staining. Because it is an aesthetic problem, the treatment  is also asthetic which is aimed at either bleaching the tooth to reduce the intensity of the staining or other modalities like laminates or Crowns. The modality best suited for your case can be determined only after a proper clinical examination. The advantages and disadvantages of limitations of every treatment modality can be discussed in detail before the treatment is planned. Please talk to your dentist about the same. Alternatively you can post clinical pictures of the case on Practo for an online consultation with a specialist. Regards.