Ajay Kumar Yadav, who hails from Jaipur in Rajasthan, was last seen by his classmates on Friday.
The student used to stay in IIT-Guwahati hostel.
None of Yadav's classmates or teachers saw him yesterday. They tried to call him on his mobile but found it switched off.
IIT-G authorities today filed a missing person complaint in this regard at the Amingaon police station.
Yadav's parents have also been informed in Jaipur.
The institute is located in North Guwahati town of Kamrup Rural district.