What such requirement/quality should a person have to get employed by a recognized hiring firm?

Besides the eligibility criteria, one should be confident enough and should have faith on his skills. He should highlight his skills and prove that only he can be the best choice. Before appearing in an interview he should complete his homework regarding every prior knowledge about the post offered and the employers as well. What is their demand and how well you fit for that post and what kind of benefit you can give to the firm, etc.