Complex sentence: He was planning a film based on the Hindu epic,'Ramayana', with Sanjay Dutt playing the role of'Ravana' before his sudden demise in December 2003 at the age of 87.
Split into simpler sentences: He was planning on the Film'Ramayana', with Sanjay Dutt playing the role of'Ravana', but then his unanticipated death stopped the making of the movie. He passed away in December 2003 at the age of 87.