No gain in dubbing it in Tamil/Telugu/Malayalam.
Neither South cares for Bollywood nor Salman is a huge star there except nizam to some extent.
Padmaavat, Dangal, Dhoom3 were few exceptions.
But if content clicks it can collect some decent amount. Knowing it's Alvira's production I don't think Salman will take any risk and if the movie turns out to be superb it'll be a treat to see the big Daddy of box office destroying all records left right and center.
Excited for this Eid as always.