I travel quite a bit in any given year, mostly Africa, Arctic & Antarctica, but Europe gets a reasonable amount of entry but not yet to India, on my List.
I also travel with a large amount of gear as mostly I Photograph wildlife, so long lenses, I frequently travel with anything up to $50k in gear, I've had 3 Countries where I have had minor issues, Russia (Murmansk) on a North Pole trip, the Russians were a PIA, had to fill in a Declaration form listing all my Gear/Equipment Numbers etc, when I left Russia, also via Murmansk, no one was interested in the Form, go figure. Indonesia, I live here & Singapore so the Indonesians always ask if any of my gear is new, I always say No, they always ask why I have so much Gear, I always say "I'm Lucky", they Laugh & everyones Happy, Australia, not because of the Gear itself but because it's always Hand Carried & the "Nanny State" have their Rules, 11Kilos of Hand Carry in Business Class, no exceptions, so I take out the 1Dx, fit the 300f/2.8, put it all onto a Carry Strap around my neck, and smile, with Customs it's always important to smile.
There's good advice in this thread, Insurance, carry Receipts etc, and these are probably the Key to trouble free travel with gear, I must admit though I've never carried receipts, although I do Insure, what ever you decide to do, Happy & Safe Travels & Good luck with the Photography.