Toonpur ka Superhero is an animated movie with voices from Ajay Devgn and Kajol.
Toonpur is basically an imaginary city here. Actually in India, animation is called 'Cartoons' in general, whereas 'pur' is a common term for a city and we have a huge number of 'purs' in India, like Rampur, Kanpur and Kolhapur.
So basically, "Toonpur = Toon + pur = Animated ones + city" is an imaginary city where animated characters reside.