IFos with Mechanical Optional

Anyone who is preparing for IFoS here with mechanical optional.
Can anyone tell me what questions are asked in the paper. As I am new and will be applying this year. Does this optional will give good marks. 
I have done my B.tech from IIT Delhi with mechanical engineering, so wanted to give a try. I am also trying for IES too..
So any seniors who have done this or taking exam with mechanical paper, please suggest