Dhanush watched director Mari Selvaraj's debut film Pariyerum Persumal, which is based on caste injustice and discrimination. He was impressed with director Mari Selvaraj and quickly signed a film with him titled Karnan. As Dhanush is riding high on winning the National Award for Best Actor, the makers of Karnan released the teaser of the film. Karnan is one of the most anticipated films of 2021 because of the first collaboration of Dhanush and Mari Selvaraj. The teaser was quite abstract showing some powerful visual of Dhanush riding a horse and a character asking him to to kill everyone and not to spare anyone who wronged them.