Complex sentence: Pandian moved on to work on "Thamizhan Endru Sol", again co-starring his father Vijayakanth in a pivotal role, but his father's ill health meant that the project was postponed.
Split into simpler sentences: Pandian moved on to work on "Thamizhan Endru Sol", again co-starring his father Vijayakanth in a pivotal role. However Vijayakanth's ill health meant that the project was postponed.