Which is most important in Campus Interview?

The Most Important Interview Non-Verbals

Many interviews fail because of lack of proper communication. But communication is more than just what you say. Often it's the nonverbal communication that we are least aware of, yet speaks the loudest. Following are the top five nonverbals, ranked in order of importance, when it comes to interviewing:

• Eye Contact – ( Unequaled in importance! If you have a habit of looking away while listening, it shows lack of interest and a short attention span. If you fail to maintain eye contact while speaking, at a minimum it shows lack of confidence in what you are saying and at a maximum may send the subtle indication that you may be lying)
• Facial Expressions – (It has continually amazed me when interviewing college students of the large number of people who were totally unaware of the sullen, bewildered, or even mildly hysterical expression plastered on their faces--often during the entire course of the interview! It's almost as if four years of college has left some students brain dead or worse. Some recruiters (not myself, of course) have been known to hang humorous labels on these students, such as "Ms. Bewildered" (who looked quizzical during the interview) or "Mr. Psycho-Ax-Murderer" (who looked wide-eyed and determined to do something, although you dare not ask what!).
• Posture - Posture sends the signal of your confidence and power potential. Stand tall, walk tall, and most of all, sit tall. I don't say this to offend the "short people" of the world--in fact, I'm under 5'5". 
• Gestures – ( Contrary to popular belief, gestures should be very limited during the interview. When you do use gestures, make sure they are sincere and meaningful )
• Space – ( Recognize the boundaries of your personal space and that of others. If you are typical of most Americans, it will range between 30 and 36 inches. Be prepared, however, not to back up or move away from someone who has a personal space that is smaller than your own. Hang in there, take a deep breath, and stand your ground. For most of us, merely the awareness of our personal space is enough to consciously prompt us to stand firm. If you have a smaller than average personal space, make sure you keep your distance so that you don't intimidate someone who possesses a larger personal space. )

Until you communicate your ideas or speak up  your aptitude  will not be clear to the interviewer. you may lose if you donot communicate.

Well i think that apptitude is somewhere helpfull for your placements , but only aptitude and bad communication will be a reason for your failure.

Because without interaction you can't achieve something, because then nobody will understand that what are you trying to  speak and for that communication is a must.

What ever Round may be communication is more important, Good aptitude helps to move to next round, but Communication is only help till the offer letter..