SK 21 (tentative title) is an upcoming Sivakarthikeyan starrer that is a production venture of actor Kamal Haasan. Rangoon director Rakkumar Periyasamy is directing the movie and recently, he was spotted at the Chennai airport with his crew leaving to Kashmir for recce. Kashmir in India has recently been of topic of interest in Tamil film circles because a schedule of Vijay starrer Leo happened there. 

Incidentally, just as team Leo wrapped and left Kashmir after shooting there for a month, team SK 21  reached the city last week to scout locations. There are also many connections between team Leo and SK 21 - 1) Rajkumar Periyasamy had assisted on Thuppaki starring Vijay in the lead 2) Leo director Lokesh Kanagaraj's last film was with SK 21 producer actor Kamal Haasan 3) Leo is part of Lokesh's cinematic universe, that also has Kamal Haasan's Vikram; some characters from Vikram will make an appearance in Leo which releases on October 19, 2023.

SK 21 is touted to be film high on patriotism and has Sai Pallavi playing female lead.