This is basically a screening round for shortlisting the students for the interview round. so, this is hell an important one. the test consists of two sections- A) General Aptitude( 2 marks each que.) and B) Branch based questions(1 mark each que.). Indiabix, pariksha.com, R S aggarwal, etc. can be very helpful for section A) and for B), you have to be thorough with your branch stuff( concepts, applications, theories, etc.)
This is the finale!! So, there is some sheer luck which might you need at this time. But the absolute key is to prepare completely for this round. During my interview, it was only one guy who took Technical+HR interview of mine. The inerview started with "Tell me about yourself". Then he asked all the Metallurgy related stuff with some applications. He also gave me a case study - for a particular application, what material will i suggest, etc. He asked me my favourite subject, topics, etc and lastly about myself which included my hobbies, my goals, strengths and weaknesses. Lastly the interview ended with greetings and i wished him,"Good day"! So, I would like to conclude that prepare very well and just be confident. Even if you are nervous, just don't show him. Best of Luck!
Perfect Preparation is the key to kill Failures/Rejection. Do your part sincerely and leave everything else to the Almighty. Believe in yourself, your hardwork and determination. All the best!