Hello,

Yes, among the list provided by UPSC you can choose any optional,but the syllabus of optional is nothing short of graduation level, so in order to minimize the study burden it's best advised one selects one's graduation course if that's there in the list, for instance engineering students can choose their subject,even a medical graduate can choose their subject as these are present in the list, one more thing is availability of study materials, that's equally important while choosing optional especially if that differs from one's graduation subject.