I have heard a lot about it, but then it has never been proven. Players from small states and places are getting chance, it shows that there is no such thing as regional bias in Indian cricket.
India is a multicultural society and Indian cricket team in some ways is the mirror of Indian society.
There are very few International teams which include players in their teams without being biased against any one, any religion, etc. Example of India, England, SouthAfrica, and Sri Lanka comes to
my mind.