A carotid body tumour is a dangerous condition, and the tumour is difficult to remove. During removal the supply of blood from the heart to the brain may be affected on one side, therefore special manoeuvres are needed to ensure that this does not happen.
In early cases, surgery may definitely be successful.
However, your brother appears to have an advanced lesion. It sounds as if this may not be removable, although one cannot be certain without seeing the patient. Your best bet for surgery is a vascular surgeon: available in Delhi at Sir Ganga Ram, Apollo, and Escorts.