If you are, then you must have watched this movie called "Agni Natchatram" in Tamil, "Gharshana" in Telugu and remade as "Vansh" in Hindi. The original Tamil film starred Prabhu and Karthik and had the famous song "Ninnu kori varnam" pictured on Amala. The movie featured the fight between step brothers and the culmination. Here is the wikipedia link http://en.wikipedia.org/wiki/Agni_Natchathiram
Similarly, there was one more movie called as "Dalapathi" or "Thalapathi" in Tamil/Telugu which had the famous song "Sundari kannal oru saidhe" and the movie had Rajnikanth who else :) playing the role of a Karna like character Surya who is separated from his mother, played by Sri Vidya (Kunti) and he is a gangster sort of, who works for the superdon DEVA(RAJAN)(Duryodhan) played by Mammooty. The movie had Amrish Puri and Arvind Swamy too donning the roles of the antagonist and the younger brother respectively. This also had a fight between the gangster elder brother and the younger brother (Arjuna)(district collector who wants to get both Deva and Surya arrested of course). In this movie, both Deva and Surya die in the end. Wiki link here: http://en.wikipedia.org/wiki/Thalapathi
Rajnikanth down south is called as SULTAN in case people don't know.
Someone in the MB team seems to have a heavy dose of Mani Ratnam, Rajnikant and a South hangover.