hi,

see NIT rourkela offers admission to mtech course on following discipline from mechanical branch,

Machine Design & Analysis

Production Engineering

Thermal Engineering

Cryogenics & Vacuum Technology

generally admission is based on gate score as well as academic scores, however Differential academic qualifications across the departments have been made considering the departmental requirement, availability of candidates in the respective departments and uniform growth of all departments in the Institute. so its totally depends on the authorities decision. however you may definitely apply for relevant discipline as well as mechanical engineering.