Complex sentence: The two leading roles were played by Siddharth Narayan and Genelia D'Souza; the other two significant parts, the parents of one of the leading characters, were played by Prakash Raj and Jayasudha.
Split into simpler sentences: The two leading roles were played by Siddharth Narayan and Genelia D'Souza. The other two significant parts, the parents of one of the leading characters, were played by Prakash Raj and Jayasudha.