According to a complaint filed by the victim's mother, the girl was raped on June 25.
The accused has been identified as Amarjeet, a tenant in the victim's house, they said.
Amarjeet had taken the girl to his room when she was playing on the terrace of her house and then raped her, police said.
The victim has been admitted to hospital where she is undergoing treatment.
Suman Dahiya, Vice President of Haryana Women Commission, visited the hospital and enquired about her condition.
Police are investigating the case, said Investigating Officer ASI Sumitra Devi.