1) Do enough research about the company and the job position which you are applying to.
2) Make sure you are prepared for the technical and non technical questions.
3) Have some meaningful questions to ask the group and the interviewer about the company and in general.
4) Always remember that some candidates come unprepared so it is always better to stand out and ask questions.
5) Do some logical thinking exercises which will help you during the interview process because some companies conduct logical thinking exercises after the interview session.
6) During the process of logical thinking a group will be split into different sub groups and they will be presented with a case sheet. As per the logic you need to solve the problem presented before you with your team mates. In certain instances you may need to describe the way you approached to the solution along with your batch mates. Also be prepared to explain to the interviewer in person.