Hindi filmmakers don't depend on Southern states because the regional film market in Tamil Nadu, Kerala, Karnataka and Telugu states is stronger than anywhere else.
Marathi and Bhojpuri, Bengali have strong roots but they don't dominate Hindi films. In Telugu states, Tamil Nadu most of the Hindi films don't get wide release as well.
Karnataka and Kerala allow different release plans for different films, based on star value. Shah Rukh Khan has great market in Nizam, Karnataka interiors and Kerala as well.
Salman Khan commands good market in Nizam but Bengal, North Delhi are his weak territories while Bihar, UP interiors love his action films. Aamir Khan depends on content and if it is anywhere decent, everyone gives it a try.
So, stars from Telugu or Tamil Cinema can look at Pan-India filmmaking as a viable option as even big Khans can't really say that they have strong markets everywhere in India.
Baahubali kind of film gave Prabhas nice footing and RRR, if it is good, can give Ram Charan and Jr. NTR better image in North Interiors as their mass films as dubs are already popular.
But young heroes shouldn't be in a hurry. Nani is the best example for everyone. He is not trying too hard to build a market in other languages but has an eye on Tamil Cinema as he earned name there with Eega.
Seniors from Telugu Cinema are also advising the same to youngsters, asking them to look at building strong market in Telugu first and then look at others. Dear Comrade team missed this simple point, feels many!