According to reports, the incident took place yesterday evening. The victim was identified as Manik Debnath, a resident of Bokulguri in Goreswar in the Baksa district of Assam.
Debnath sustained burn injuries from the attack. Officials said that they suspect a family feud behind the attack.
The victim's wife said that there may have been some personal enmity which led to the incident.
A group of four miscreants resorted to throwing acid at the victim as the conflict turned violent, according to them.
The accused were identified as Bipin Rajbongshi, Deven Rajbongshi, Kanak Rajbongshi and Pinku Biswas, police said.
They added that the victim was returning home from work in the evening when he was attacked.
Meanwhile, he was rushed to a village hospital following the incident.
Officials further informed that Debnath has been shifted to the Gauhati Medical College and Hospital (GMCH), where he is currently receiving treatment.
Doctors at GMCH informed that Debnath is in an extremely critical condition and needs constant monitoring.