India has a wide variety of climates. Its geographical range and topographical diversity are such that you can encounter an alpine climate in Ladakh, humidity in the Himalayan foothills, dry or humid tropical in South India, and semi-arid to desert in Rajasthan!
Generally, anticipate little rain except in the Himalayan foothills, and rather pleasant or even hot temperatures except in the Himalayas.
Always bring rain gear or waterproof clothing.
Consult general information sites and the list in your Detailed Travel Program to find out what type of equipment and clothing to pack for your trip