The boy was kidnapped from his house in Hojai in Nagaon district on July 6 allegedly by his father's brother Fakrauddin Ali and another person Safiqul Islam and was taken to Seppa in Arunachal Pradesh, police said.
The boy was later shifted to Panchmile area near Tezpur from where he was rescued by the police last night.
The police arrested Fakrauddin but Islam managed to escape and a massive hunt has been launched to nab him.
The police suspect that the boy was kidnapped to be sold in Arunachal Pradesh.