Complex sentence: Initially, A. R. Rahman was signed in to compose original songs and background score for the film, but he opted out of this movie, as T-Series did not agree to share the copyrights of music with him and the lyricist.
Split into simpler sentences: Initially, A. R. Rahman was signed in to compose original songs and background score for the film. But the maestro opted out of this movie, as T-Series did not agree to share the copyrights of music with him and the lyricist.