Hi Praveen & Vasanth,
You should provide the project itenary for the duration that's requested on the initial I-129 application form, As your employer has sufficient work for you at the location mentioned in your LCA & I-129 for the duration requested, which I assume to be true. But normally work-orders are signed for 6 months or 1 year at a time. If you have it for the whole duration, you may get approved for the entire term requested, else may end up for partial term based on my experience. I am working on Employer - Client Model, No Vendor's. This is not a legal advise.