I'm not sure about Sri Lanka, but i've backpacked through India.

All I can say is DON'T TOUCH THE WATER! Tap water, ocean, rivers, any water. If you have a cut it will get infected for sure. India's sewer system and general hygiene is a little behind the eight ball.

Also if you're backpacking, you'll probably be getting around on trains, they are the easiest. I wouldn't wanna be lugging kiting gear around in those crowds. It was hard enough looking out for the one backpack. Beware of scams and theft.

Sri Lanka might well be awesome though

Good kiting all year round in Lanka, the good windy seasons on both sides of the island at opposing times of year. Im 80k and i had a 12m but i wish i had a 10. it can get pretty windy. Core kites are manufactured there and there are a few other local kites so you could find something if you had the time and the money.

I spent 6 weeks in Goa Oct-Nov and there was no wind. At all. Some ruski was there with kite gear and he got it in the air once. Water was clean there tho and the fresh seafood was the best food I had in India.

I did 4 months in India and my opinion is that the extreme north (Himalayas) and south (Goa/Kerala/Sri Lanka I guess) are good, the middle is just terrible. India is the only country in the world I'd recommend staying on the beaten track. Take a tour. There's nothing to see off the beaten track, just sh!t and rubbish and thousands of staring eyes every move you make.

I've backpacked in India 3 times and Sri lanka also.
India is hard enough to travel around without humping around a load of kite gear around, if your really keen do it but take a big kite 14/15m. You might get lucky.
Sri Lanka a better option i was there Nov/Dec but again it never really seemed any good for kiting.