Dandruff is at times very obstinate. you may have to try different anti dandruff shampoos, ketoconazole containing shampoo, Seldun/selsun etc. whichever suits you is the one for you. See if your skin is very oily or dry. Sometimes if scalp is very oily, may be the cause or on the contrary very dry scalp may also be the cause. Use a conditioner if skin is dry.
Health Tips
Wipe off dandruff from the head by tilting the head down & shaking off the dandruff from head, eyebrows & moustaches etc. Do not share comb with anyone. Gently massage your hair yourself which will increase blood circulation to the scalp, without oil if skin is very oily or with warm oil if it is dry. Eat good diet. You may try Cap Evion 400 mg once daily a week.