I am a Indian Citizen and will be travelling to Lyon (France). Right now, I am just checking various flights. I haven't decided, as most of the flights transit through a Schengen country, Middle Eastern country, or Russia.
I want to be sure about the transit visa requirements in each country before making flight reservations. While I've checked transit visa requirements of many countries, most of these answers are from forums. I keep seeing posts that say "as long as you are not leaving the airport you do not require a transit visa," which is not necessarily the case.
I do understand that it depends on your nationality and duration of layover, but I want to find the genuine source to get the answer regarding transit visa of a country.