Complex sentence: Sridhar had originally planned to cast Gemini Ganesan and Savithri as their dates were not available, he made the film with Muthuraman and Devika so that the film will be completed in a short time.
Split into simpler sentences: Sridhar had originally planned to cast Gemini Ganesan and Savithri. As their dates were not available, he made the film with Muthuraman and Devika so that the film will be completed in a short time.