The majority of women in India are still living in poverty and can’t afford tampons. Moreover, most villagers have taboos about menstruation that prevents them from openly experimenting with different kinds of feminine products. Since many poor people still do not even have regular access to toilets, tampons are not a priority.
Even middle class women, however, rarely use tampons. It is still the norm in India for women with disposable incomes to use sanitary pads. Most middle class women seem happy with pads, but I think it is a good idea to dispel some myths about tampons in order to give women and girls a greater range of choices.
Americans in India will find tampons in most large city grocery stores, but they are very difficult to find elsewhere. Also, you may not find the brand you want. For some reason, OB (without applicator) seems to be more common here.