Welcome Meena.
Pl. share what you learn with us.
I guess the language and castes don't have a very high correlation. Its more to do with the region you are staying in. People from the same castes staying in different regions generally speak the local language of that region and people of different castes and religions staying in a single region would speak the common language of that region.
Is there something I am missing here? Are you talking about language or the minor dailect variation within a major language that the different castes may have?