India's Central Drugs Standard Control Organization (CDSCO) has established procedures for the import of small quantity of drugs for personal use "for the needy patients of India."
Generally, an individual can import a quantity not to exceed 100 "average doses" as long as the drug is part of the "bona fide" personal luggage of the individual and is declared to Customs.
However in "exceptional cases," an individual may import "a large quantity" for personal use as long as the quantity is deemed reasonable "in the opinion of the licensing authority" and is covered by a prescription.