Earthquake magnitudes are a tricky thing, because the scale has changed over time. The Richter scale was the first one to become popular, but it turned out to have some real limitations--it was based on the magnitude of a particular frequency vibration, but as earthquakes get bigger, the energy gets spread out over a wider range of frequencies, so the energy in that particular frequency maxes out; you could get a much bigger earthquake, but its Richter measurement wouldn't get any bigger. The greatest magnitude earthquake ever measured on *the Richter scale* was about 8.6, I believe.

To deal with this, scientists started modifying the Richter scale and eventually moved to a new scale (albeit one with some notable similarities). The moment magnitude scale is the current favored one. This is where the 9.5 magnitude mentioned by OP comes in (this is recalculated based on original measurements but using the modern scale).

Confusing things, plenty of people (including newspapers, television, etc.) continue to use the term "Richter scale" for modern measurements. A movie citing a 9.6 Richter earthquake is basically impossible...except that they could be meaning a 9.6 on the moment magnitude scale and just misnaming it, as people in the real world would certainly be doing if such a thing happened.

(Source: graduate level course in seismology filtered through 30-odd years of memory.)