Unless there was some really screwy calender system involved, so that really Li was only 98.5 (98.5 = 197/2) in sidereal years, or something, I don't see how it's possible. Mr. Li was probably exaggerating for "spiritual value". Interpret that as you will. It's also possible, given the widely varying numbers that Li Ching-Yun gave in different sources, that he himself did not know exactly how old he was, but simply made up a very large number that would make him by far the oldest person in whatever situation he was in at the time he was writing. So no, as far as we know, it's very extremely rare for humans to live beyond 120 years, and 197 is firmly into "almost certainly a hoax".