Campus placements are not that tough to crack if you have praticed enough. There are 3 main things you need to be ready with as a minimum before placements begin

1. Written/Aptitude skills - Companies donot have time to interview all students ,since there are hunderds of application. So there is always a screening round which tests aptitude or coding skills. There are tons of questions and sample questions online for practicing. The are usually 4 sections. Quant,Logical reasoning,Verbal and Coding.

2. Group Discussion - This is very predominant in MBA , but for Engineering this round is less frequent. There are 5 to 10 candidates put into a group with a topic to discuss. Practice this with friends because GD is quite tricky where you need to know when to enter a discussion, when to pause, how many entries to make and most importantly how loud and what tone to speak in.

3. Techincal round - Practice all you programs of C and Java because this is bare minimum that panels expect. Next thing is prepare your resume very well, you should be able to answer question that comes from your CV/Resume. Last but not least, you should be thorough with your own stream ,example if you are a EEE or Mechanical student, then basics should be clear with atleast 1 fav subject with full knowledge

4. HR Round - These are mostly hygene questions. You should know yourself and your resume well, with questions like tell me about yourself,what is you strenght and weakness, where do you see yourself 5 years down the line? So practice by talking to yourself in the mirror. 90% candidates dont do this probably beacuse it looks dumb. Next thing is ask your friend or family to take your Mock interview. Be humble and dont be overconfident.