By default, SharePoint supports English and Hindi among Indian languages. Is there any way we can incorporate other regional languages like Tamil, Telugu, kannada etc...

Also, the Language Interface pack has all the above regional languages. Can that be integrated with SP2013 ?

If there is an LP for it, you can install it. The list of LPs are available at https://technet.microsoft.com/en-us/library/ff463597.aspx, and it doesn't appear to include those regional dialects.

HI karthik,The LP's can be installed in the farm and will set for those languages if the LP's are released from MS.Please check the link to down load the LP's.

http://expertsharepoint.blogspot.de/2013/12/sharepoint-2013-language-pack-and-cu.html