The man, identified as Pranab Boro (45) poured petrol on himself and set on fire during the agitation organised by the by Krishak Mukti Sangram Samiti (KMSS) and various Unnayan Samitis.
He was admitted to the Gauhati Medical College Hospital in a critical condition with 100 per cent burn injuries, hospital superintendent Dr Ramen Talukdar said.
The KMSS and other organisations in support of their demand hit the road threatening to disrupt the land patta distribution programme of the state government at the Sankaradeva Kalakshetra today.
A function for the land deed distribution, to nearly 500 landless people of the city, however, took place as scheduled and was attended by Chief minister Tarun Gogoi, sources said.
KMSS leader Akhil Gogoi blamed the chief minister for Boro taking such a step.