Well, lets consider the scenario. The advent of the placements started in most of the engineering colleges and multi-national companies coming on the campus for recruitment. The students starts to prepare for the campus. They Study the company background, their activities of what the company does, who are the owners, their history, goal, vision and mission. Then the placement cell gives details about the recruitment process, where various rounds for the selection to be conducted are described. With most of the company comes first the screening test. This may include "Quantitative Aptitude and Verbal Skills". The next is the technical round. This includes may be the Technical Personal Interview or the written test. Followed by the HR round of interview and if applicable the MR Round.
Now what flaws and what skills are required in each round? There are many flaws and mistakes done by the students that don't get hired. If you want to get hired in a company then you need to be serious about the entire recruitment process. If you're planning to be placed in a well established MNC then 2 - 3 days of preparations doesn't pay off except that you're a genius and talented enough. You need to cultivate the habit for preparation. You need to keep preparing even when no campus drives are coming up. This regularity and commitment to yourself and your future career is very important asset.
If you really plan to get hired in any MNC, then cultivate the habit of preparing for the skill set, every evening and morning 1 hours. 2 hours a day won't harm you daily activities. Besides, getting placed is the only aim for which you have done all the previous educations - primary , secondary and engineering studies. So give your BEST efforts. You'll be really gifted for all the efforts that you have invested in this period of your life - the final year. It'll surely pay you well heavily.
Sources for preparing :
- Apptitude and Verbal Skills : R.S. Agarwal Book and IndiaBix.com
- Technical Section : IndiaBix.com, Wikipedia.org
- HR Questions : Google -> "company name"+"hr questions", Indiabix.com