Rupali,
I just want to commend you for attending a job fair for the first time. This past week, I attended a job fair for the first time as well, and have empathy for you and your situation. In my case, I was nervous about the fair because I did not know what to expect; it sounds as though you had similar uncertainties. I have several comments on both your posts and reply posts from individuals visiting this website.
First of all, try to put yourself in the recruiter's position, who has probably spoken with many people, been on their feet for several hours, and is growing tired as the day progresses. It is probably best to attend the job fair as early in the day as possible to avoid this situation as much as possible.
Simply handing your resume to a recruiter after waiting in line is probably not a wise course of action. Introduce yourself and ask what the firm currently needs. In general, firms are looking to fill current needs. Act sincerely interested in the recruiter's response because you are sincerely interested. Ask questions and follow-up questions to get a good picture of what the firm is looking for. At the appropriate time, pull out your resume, and before handing it to the recruiter mention that you are looking for a position to meet those specific needs...and the skills you have satisfy the requirements of the position.
I actually had a similar problem as you at the job fair I attended last week, except most firms were looking for entry-level individuals. It was held at a local university. Probably over 90% of those in attendance were new-grads or soon-to-be new-grads.
But how did I know this? Because the waiting lines were so long (I usually waited at least 15 minutes...a couple firms, such as IBM, required me to wait 45-60 minutes), I made myself feel more comfortable with the new experience by chatting with individuals in front and back of me in line. Some even gave me feedback on their experiences at the firm, which helped prepare me as I approached recruiters at firms later on in the day. (I knew early on that most of the firms were looking for entry-level employees, and I made an effort to mention early on in my discussions with recruiters that I was experienced. It is important not to waste their time.)
In one instance, I started a conversation with a recruiter on break (who was at the fair for a non-IT department) while waiting for the firm's other recruiter. This practice chat helped prepare me for the real chat I was about to have, and she was even able to answer some questions for me.
A small fraction of the firms I stopped by had potential work for which I am interested. I made an effort to request leads from those firms that did not match my employment needs. For example, over the past week I have been involved in email conversations with two of the recruiters. Remember, when attempting such a strategy, the worst thing a recruiter can do is say "no, I have no leads or advice for you". Since both you and the recruiters are spending many hours at the job fair, make every effort possible to take advantage of the situation.
Check out
http://www.asktheheadhunter.net, I found the website invaluable.
Best wishes for your job search.
Erik