A total of 87 reptiles and mammals were found in the baggage, including chameleons, snakes, a large-beaked parrot, red-eyed squirrels, bats and monkeys.
Some animals were wrapped in paper, others in plastic containers, photos from customs at Bangkok's Suvarnabhumi Airport showed.
The six, bound for Mumbai, were arrested on Monday, authorities said in a statement.
Thailand, which borders four countries, has seen its fair share of illegal wildlife trafficking and customs officials at Suvarnabhumi often seize reptiles and small animals in luggage.
There is high demand for animal products in countries including China, Myanmar and Thailand, where they are used in traditional medicine or consumed directly.
(Reporting by Chayut Setboonsarng; Edited by Nick Macfie)
