Dear Sir If the fingers are black, he needs urgent consultation with a Vascular Surgeon or General Surgeon Please don't delay with home remedies

Hello. He needs to get evaluated for present condition. There are many treatments available. In Ayurveda, there is a treatment plan like raktamokshana using leeches which will correct the blood flow and reduce the condition. Further it depends on his various other condition as to medicines are concerned. Else, you may approach a vascular surgeon who can evaluate the condition in modern medicine.