There is a huge market for the Hindi dubbed versions of South Indian mass masala flicks, from Tamil and Telugu cinema. Leading Tamil actors like Karthi and Vijay Sethupathi have talked about this in their recent interviews about how they are recognised by the North Indian public when they go shoot in different northern regions, thanks to the reach and penetration of the Hindi dubbed versions of their films.
The Hindi dubbed versions of these films are screened on leading satellite channels and also on YouTube. The TV rating and the online views are really good, and producers are able to get a good rate for the Hindi rights. This sum goes a long way in enabling producers to recover their investment in the film, pre-release itself.
The recent news on this front is that the Hindi dubbing rights of Thalapathy Vijay's Sarkar, for both TV and online showcase, have been sold for a record-breaking 24 cr, a new benchmark for a Tamil film.
RC 12 (Ram Charan's upcoming film with director Boyapati Srinu) fetched 22 cr for its Hindi dub rights while Maharshi (Mahesh Babu’s upcoming film with Vamshi Paidipally) is said to have fetched 25 cr for its Hindi dub rights according to the grapevine.
We can't consider the Baahubali films in this discussion as they had their Hindi dubbed versions released in theatres to massive success.