Vimana are not unique to India and there are references from all over the world and include the Egyptian Saqqara Bird, the pre-Columbian golden airplane models, the Greek Icarus legend, the Chariot of Ezekiel, the Nazca runways (lines), The Abydos carvings, The Tassili rock paintings from Algeria and the Chinese references to Lu Ban’s wooden aircraft that flew great distances. Naturally, these references are often dismissed by modern historians as simply impossible but there can be no doubt that humanity has a collective memory of have once been able to fly in ancient times.
Or even just to have worshiped flying beings. Modern fiction is full of fantastical and impossible things. Are we to believe that people in the ancient world were incapable of flights of fancy and everything they wrote and made must be taken absolutely literally?
A vimana, which from googling appears to be some kind of flying temple in Sanskrit myths, does not appear to have actually existed.