One Phawang Ngonpa, a self-styled sergeant of NSCN (IM), surrendered at the Namtok police station in Arunachal Pradesh’s Changlang district on October 5.
The 30-year-old member of the insurgent group is from Phangsung village and one of several who surrendered, officials said.
An enquiry revealed that the NSCN (IM) had radicalised him in 2015 with a promise of a job and salary in the outfit.
Officials said he realised his mistake of being misguided after joining the outfit as his life became miserable and health deteriorated over a period of time due to absence of treatment in the jungles.
He later took the decision to return to his village and live a normal life with his family.
On Wednesday, Changlang Deputy Commissioner Devansh Yadav issued Ngonpa a surrender certificate to let him live life as a free man.
Changlang SP Mihin Gambo has, meanwhile, appealed to all the misguided youths who have left their family to join an underground outfit to return to mainstream society and live a normal life with dignity.