Indians, like other Asian peoples, prefer not to say no. The Indian wiggle, a very loose wobble of the head from side to side on the neck, can mean yes, no, or anything in between. When it is accompanied by an indeterminate sound, a little like ‘hunh’, it often means yes. A direct ‘yes’ can be lessened or emphasized by a wiggle. It can be quite confusing.
A similar conundrum for the visitor to India is the phrase ‘no problem’. It is said that in India, “the only problem is ‘no problem’.” Since Indians prefer not to say no, they may, out of politeness, reply ‘no problem’ to a request, when actually satisfying it requires an enormous effort on their part. Be careful not to make a request if you don’t know how difficult it might be to satisfy.