Pls try paste of aloe Vera hibiscus flower nd over night soaked fenugreek seeds mixed wth curd.also add a table spoon of coconut oil nd honey to it.apply on scalp n hair keep it 45-60 minutes n wash wth mild shampoo.do it every week it will make hair smooth shiny and dandruff free.
If you are applying Mehendi just stop. It dries skin more and that causes Dandruff. Massage with olive oil and than give Hot towel treatment. Aloe vera gel also is very beneficial.