Can I list a working(unfinished) project on my resume?

Of course, you can if you think your project holds the best place in the resume and it is valuable to be in your resume. I think that most interviewers/potential employers would be far more interested in the quality of your work than the overall outcome of the project you worked on for someone else, particularly since that outcome is often completely out of your control.

As a general rule of thumb, the company will care more about the technical experience you gained from that endeavor than they will about the success of the project.