"Maharashtra is a great state. There is nothing wrong in promoting Marathi. But, at the same time do not kill Hindi and Bhojpuri," he said to reporters in neighbouring Virar in Thane district.
The comments came against the backdrop of the MNS chief taking up the issue of Marathi filmmakers.
Actor Rajkumar also worked to promote and encourage Kannada movies in Karnataka, he said.
Raj Thackeray had recently warned multiplex owners to show Marathi movies at primetime hours in their halls.
Last week, Singh sprang a surprise by going soft on Raj saying that the MNS chief's statement regarding migrants spreading malaria was not from his heart.
"Although alleging that migrants are spreading malaria is not good, what he (Raj) said was not from his heart," Singh had said at a Lokmanch Party function here.
"I have met Raj several times along with common friend Lalit Soni and I found him to be a very soft person with immense self-esteem," he said.
The MNS chief had blamed the migrants for the spread of malaria in Mumbai as they had flooded the hospitals, leaving no space for patients who hailed from the state.