Superintendent of Police Prabhat Kumar said the three-and-half-year-old boy suddenly came infront of the vehicle of JMM MLA from Torpa constituency, Paulus Surin, near Parenga village and was critically injured.
The MLA's driver was driving the vehicle in which Surin was travelling.
The boy was referred to Rajendra Institute of Medical Sciences, Ranchi, where his condition is stated to be critical, the SP said, adding that a case has been registered.