What Happens When Schools Cannot Provide A Placement Exam?
Schools and even individual departments probably differ greatly on how they handle such issues, so your best bet is to talk to your academic advisor as soon as possible to figure out what your options are. At many schools the "director of studies" (undergrad or graduate) for a program has some latitude to waive requirements and allow students to make substitutions—I know that was certainly the case for me when I was an undergraduate student because I had come into the major with a relatively unusual background that meant I needed to replace some classes that could not be taken (I had taken similar courses in a different "track").