The South Indian film industry, especially the Telugu and Tamil film industries, have been known to hire actresses from the North for their films, particularly from the nineties. These actresses used to simultaneously work in Bollywood as well. This trend started to deteriorate in the 2000s when actresses couldn’t juggle Bollywood and the South for some or the other reason.
Down the road, South Indian actresses, even if they were from the North, opted to stick to the South, and many even rejected Bollywood offers. While some tried to make it in Bollywood as well, they eventually lost prominence everywhere. After some gap, with language boundaries having been blurred, thanks to the success of pan-Indian films, it looked like actresses had a wider scope to perform in.
As everything seemed to be going well, with Alia Bhatt making her Telugu debut with RRR and even potentially to be NTR30, it looked as though many other Bollywood actresses would follow suit. However, after the release of RRR, for some reason, Alia dropped out of NTR30. Now, the situation is back to square one, with not many Bollywood actresses ready to come South, in the fear that they wouldn’t get much scope to perform as they do in the North.