First round: Written test consists of Aptitude questions (50 questions) and 10 questions on your department related and 2 programs(Basics)and Essay Writing.
Aptitude questions where basic refer indiabix
for HR round: be strong in resume content , C and DataBase
There may be three techinical round but if you answered well enough in first then you are selected.
they are not looking for answer alone they check whether you are confident and how you approach problem etc.
In technical round they would ask problems from array and String