Koch, who was serving as the general secretary of KLO surrendered along with his wife Jugli Koch, also known as Swapna Burman at the state police headquarters Bhabani Bhavan.
The Director General of Police (DGP) Manoj Malaviya was present as Koch laid down arms today.
According to reports, he also handed over an AK-47 rifle.
It may be noted that KLO was formed with the objective of carving out a separate Kamtapur nation from India. They are a far-left militant organization based in the Northeast of India.