Another 10-year-old boy who too had suffered injuries in the incident is undergoing treatment at a hospital here.
The mishap occurred at Moula Ali railway station on March 24 after two boys went atop the coach of a passenger train and one of them started clicking selfies.
"Three boys had went to the railway station and two of them went atop the stationary coach. When Sai Kumar (13) was taking selfies, he and the 10-year-old boy came in contact with a high tension wire, resulting into burn injuries to both of them," Nacharam police station Inspector N Pravindar Rao said.
Police have registered a case under section 174 of CrPC in connection with the incident.
The Inspector said the case will be transferred to the Railway Police as the incident occurred under their jurisdiction.