Complex sentence: Upon the completion of "Velayudham" (2011), Vijay announced his next project to be with R. T. Neason, who had worked in "Velayudham" as an assistant to director Jayam Raja.
Split into simpler sentences: Upon the completion of "Velayudham" (2011), Vijay announced his next project to be with R. T. Neason. Neason had worked in "Velayudham" as an assistant to director Jayam Raja.