Well-known Malayalam actress K.P.A.C. Lalitha, known for her work in National Award-winning films "Amaram" and "Shantham", plays a pivotal role in filmmaker Mani Ratnam's upcoming Tamil romantic drama "Kaatru Veliyidai"."She has joined the sets in Ooty. She plays a Muslim character in the film," a source from the film's unit told IANS.The film features Karthi and Aditi Rao Hydari in the lead while Shraddha Srinath, R.J. Balaji, Delhi Ganesh and Vipin Sharma are part of the supporting cast.Karthi is playing a pilot in "Kaatru Veliyidai", which features Aditi in the role of a doctor.Produced by Madras Talkies, the film has music by A.R Rahman and cinematography by Ravi Varman.