They basically check the technical knowledge about your particular domain. Since my being chemical engineering, they generally prefer asking on heat transfer, fuel engineering, knowledge on industrial engineering particularly related to petrochemicals. Interview is not stressful as one think of but you must be good in your technical skills. They do consider your extracurricular activities. Be confident and be relaxed while interview.

First a test with a very easy aptitude and core discipline related questions. Then only one round of interview and it was also very easy. See they try to hire as much as they can and the losers of all losers get placement in this 'GREAT' company. Then you go in the firm and find out that the number of educated and literate people are very less and all the old employees who has no other option are like stuck in this firm. Here you will not find a single person who is like-minded and all good for nothing arrogant, miserable gujjus!