Anything that runs on 220 Volts, you can't even plug
it in, leave alone expect it to work.
Any winter clothing other than a sweater, good quality hand gloves and cap.
Do not bring fresh plant products such as fruits,
vegetables or meat products, you'll have trouble at customs. Pickles are
ok, and its safer to answer "No" when you're asked about fresh fruits and
vegetables.
Gifts for people unless they are authentically Indian
and of good quality
Too much formal clothing. Most people dress casually
and comfortably.
For Girls, excessive jewelery. Again, same reason
as above, it isn't appropriate for daily wear, but good only for special
occasions.
A Truckload of spices - you get everything you need
here. (Just bring the stock for 3 months)