After Yuvan Shankar Raja walked out of Viswasam, the makers of the film have been in talks with a few established names to compose the music. Reliable sources confirm that Sam CS and Anirudh have been approached. 

A source adds, "Sam would love to score music for such a prestigious project. Moreover, he has been wanting to work with Ajith for a long time. Though talks have been initiated, nobody has been officially finalised." 

So, we need to wait and watch if Anirudh will be collaborating with Ajith again after Vedhalam and Vivegam, or if it's going to be Sam.