You are correct and it is common in most of the country among all castes, one example will be the great film director Satyajit Ray who married his maternal sister. In most of my stories that is why i consciously take that relationship may it Nanad ki Training or even in this one, Joru Ka Gullam Guddi is maternal sis . Mohe Rang de also follows the same template.
But prohibited relationship varies from area to area, however, what i have mentioned as hard incest are not permitted anywhere for marriage. Hence it will always be incest a foray i made in Chhutki.
