Firstly,they told me to go through the resume,then they asked questions from my training.
I have done training in railways and powerplant,they asked me to explain the differential mechanism of railways...
After 2 more questions on railway, they moved on to the power plant,they asked me to explain the working, different components, different types of boiler,bouler mounting and accessories,effect of pressure on condenser and boiler, concept related to cooling tower,stack effect...and many more
After technical,Hr interview took place,it was general HR questions.. available on internet.
Good luck