Highest grossing films of the year can belong to these Pan India films and they are giving a good competition to Bollywood films.
Bollywood really has to up it's game and start producing such huge canvas films. The problem is that while a Bahubali 1 & 2 will get 119cr+ and 500cr+, 2.0 will get 186cr and Saaho will get 148cr in the Hindi version, the biggest Bollywood films don't perform that well in the dubbed versions and even the original Hindi films don't collect earth shattering numbers down south.
If I am not wrong, Dangal is the highest grossing Bollywood film in dubbed languages at around 12-13cr. Again figures might be wrong, but look at the comparison. 4 films doing more than 100cr (one 500cr) in the Hindi version and all the Pan India films you just mentioned have the potential to cross 150-175cr on the WORST case, original Bollywood films aren't able to find that level of penetration into the southern markets.
So many big canvas Bollywood films have released in the last few years, but they haven't found as much success as these 4 south indian films have had in North India. If Bollywood isn't able to find as much success down south, then it won't be long until TFI becomes the bigger industry.