The test consisted of 2 sections, department specific technical questions section and an aptitude section. Both the sections required basic knowledge of the topics concerned.
In this round, questions were around the activities and internships mentioned in the resume, however it would be beneficial if you have a couple of favourite subjects and have thorough grip of the topics in them, along with them prepare a basic template for some basic questions asked in the interviews, this would definitely come hand at the 11th hour. Maintaining confidence throughout the interview, whether you know the answer or not is very important, there is not harm in accepting that you don't know something.
Clearing aptitude test is the primary step in any company's campus drive, taking timed tests from sites like Pariksha... would suffice, no matter how good your personality, you wouldn't be able to showcase it,if you don't clear the first step.
Do not try to fool the interviewer, he/she has seen many like you... Apart from the basic interview questions and core knowledge, prepare some interesting questions to ask the interviewer at the end of the interview , this might give you an edge over the other candidates, before sitting in any interview, go through the company website this will help you understand the company better.