It is your responsibility to find an IUP faculty member willing to guide you through the thesis project and give you a grade at the end. This person is called your thesis director. How do you find such a person?
First, your topic and director have to be a match. If you want to do a thesis on forestry in Northern Burma, you will need a director who will be able to help you. In some cases, the topic you are thinking of may not have an exact match among the faculty. What if you want to work on suppression of spirit mediums in Late Yi Korea? We don't have any experts on Korean popular religion, but we do have faculty who work on contemporary Buddhism and on social reform in China. Most faculty are very willing to help you out, but they also know that past a certain point they really can't give you useful advice. There may be some topics where it is not possible to find a faculty member to direct a particular thesis. Then you will need to find a new topic.
How do you know which professors have which expertise? The Asian Studies website will give you a general idea. The courses that faculty teach and their publications are also good clue. Often the best information will come from your academic adviser because faculty colleagues always know each other's work well.
Second, your thesis director should be someone with whom you think you can work well. Professors and students are no less human than anyone else, and some personalities and learning styles match better than others. In many cases, you will already know your director well from prior coursework, and he or she will know you. If you do not know each other well, you each may want to spend some time in conversation before making a commitment. Remember that the professor is making a large time commitment to you, just as you are to the project. You both need to feel good about what you are undertaking.
You should not be hesitant about approaching a professor. Most professors love to have thesis students, and they will consider it a compliment that you are asking them to be your director. It is, of course, possible that they may already have taken on as many thesis students as they can handle, or made other commitments that make it impossible to work with you in any given semester. But, the vast majority will be eager to work with you if they can possibly manage it.
Professors who may seem distant or even daunting in other circumstances can become suddenly enthusiastic when they find out that you are passionate about the very same things that they are. Just as in other human relationships, common interests and common tasks make a good foundation for cordiality and mutual respect.