For SBI clerk interviews basically questions are based on economics and accounting. They test the IQ level of the candidates and their day to day problem solving capacity in the banks. What I can suggest you is to maintain your cool and stay calm and composed throughout the interview for the questions would be based on general knowledge types. All the best for the interview!!!
Most of the questions are based on accounts.. And some others like
What is ATM?
What are the functions of RBI?
Who will issue one rupee notes?
Who will issue currency notes?