Where in India did you consider going? How long are you staying?
I highly suggest going to Hampi if you're near Goa/Karnataka.
If you're up north, I think the himalayas will be already quite cold, but if you go right now, you may still get the charas harvesting season (if you're into that sort of thing). If you go parvati/kullu valley, I suggest going to smaller places avoiding Manali. Kheerganga hotsprings are very special, and so is Malana. There are many amazing hikes, the Chandrakani pass was incredible, but better get a local guide (if you're there shoot me a pm I might give directions to one). I hear the pass to Spiti Valley is amazing too. But I would avoid all these places in winter, better either go now or wait for spring.
I'd love to go to Leh and Ladakh next time too.
In winter I'd probably head more south, Goa, Karnataka, Kerala, Andaman Islands etc...
Have a great trip ! Let us know how it goes!
Take pics and post here