Traveling to India, it's important to note that many of the clothes that we wear at home are not appropriate for India, either in terms of the climate or in terms of the culture. It’s important to be familiar with the Indian dress code and the reasons behind it as they are much more conservative culture. The climate is also very humid, so cotton is best to keep cool. Traditional Indian clothes are more comfortable than Western clothes, especially in the heat. Even in extremely hot weather, having your arms and legs covered with very light cotton actually keeps you cooler than shorts and halter tops can. And most Indians love it when you wear Indian dress because it shows your appreciation of their culture. Wearing traditional clothing also serves as a great ice-breaker; many people will comment on it, and you will find that the comments are generally very appreciative.
While it’s OK to wear Western clothes most places, it’s essential to wear them in a manner that is respectful to the very modest Indian culture.
For the ladies, it's required that you cover your knees, upper arms, shoulders, cleavage and midriff. It’s acceptable for your midriff to be exposed when wearing a sari, but not otherwise. Shorts and short skirts are not acceptable. Tops should not show your cleavage or be too tight or revealing. It's inappropriate to wear sheer blouses, shorts, spaghetti-strap dresses, bikinis, tank tops, etc. While sleeveless tops are becoming more common in some of India’s big cities during the hot season, in general they are not acceptable; however, short sleeves are usually OK.
For the men: tank tops and singlets are not acceptable. T-shirts covering upper arms would be more suitable.
When wearing pants, go for loose, tunic-style tops that cover your crotch and buttocks. At home, many of us like to wear our blouses neatly tucked into jeans or slacks, but in India, it’s better to let them hang out.
If you bring a swimsuit, it should be a conservative one, no matter where you plan to wear it; a one-piece is preferable for ladies, while board shorts would be better for the men. On the way to or from the beach or pool, or whenever you are interacting with locals, put something modest on over your swimsuit. Bikinis are not acceptable.
In certain conservative locations and in many places of worship, you will also need to cover your head. Observe what the local women do, and do likewise.