Marathi films have a good market in most parts of Maharashtra and even in Mumbai and Pune. When I went to watch "Njan Prakashan" in a Mall in Navi Mumbai, four Marathi films were running successfully with heavy rush! Marathi films are watched mostly in Goa and North Karnataka apart Maharashtra. There is no outside market. Marathi has couple of films in the Rs. 100+ club. Regarding, Kannada, the recent KGF has crossed Rs.200 crores and may place Kannada now above Malayalam in collections. Regional films are making a mark not just southern films. Marathi is definitely making a mark, Bengali and Punjabi may not. Regional films can make it big if the a big budget film is dubbed in Hindi and some other major languages.
The fact is that the regional film industry(there are many in North India) in India except for the four South Indian languages are not so solid or strong enough. Still Bollywood is dominating there except some films once in a bluemoon in Punjabi or Marathi or Bengali. In terms of market and money the order in India is 1) Bollywood 2) Telugu 3) Tamil 4) Malayalam/Kannada(not sure both have somewhat similar size though Kannada I think has a bigger domestic market and Malayalam has a bigger outside state market) even though there are contradictory opinions on which industry is bigger(Tamil/Telugu). Rest of North Indian regional industries still face threat from Bollywood and are just evolving