Manoj, here in the U.S. we're all but required to make a fundraising sample before we begin editing our film, usually somewhere between 5 and 15 minutes. We complain like hell, but it actually forces us to think through our story and work out structural issues. And it's a great opportunity to get feedback from others.
Since you're a D-Word member, this discussion actually belongs in the Works in Progress topic (the Mentoring Room is saved for Enthusiasts who have very limited access to the topics). There you'll find many other examples of samples our members are making.