The Bad Batsman

Naina, Sunder and Bablu are here at the station to file an FIR. Naina tells that she and Bablu are in love and suddenly Bablu has started behaving like a mad man. This was due to a hard hit by a ball to his head. When the batsman is told that the six he hit damaged Bablu's head, he collapses. He also reveals that he is not a good batsman and hasn't scored a total of six runs in his career. How will the inspector get to the bottom of the case?