While it is true that earthquakes have the potential to cause significant changes to the Earth's surface, there is no evidence that an earthquake has changed the course of the Ganges River in the past. The Ganges River flows through a relatively stable tectonic region and is not known to be situated in an area with high seismic activity.

River courses can change over time due to various geological processes, such as erosion, sediment deposition, and tectonic movements. However, these changes typically occur gradually over long periods of time and are not directly caused by single seismic events.

As far as the Ganges River is concerned, its path and course have been shaped over millions of years by a combination of tectonic activity, changes in sea levels, and erosional processes. The river's present form is influenced by factors like regional topography, geological structures, and the amount of water it carries during different seasons.

Earthquakes, especially major ones, can certainly reshape landscapes and cause ground deformation, but these effects are usually localized and may not directly impact the course of major rivers like the Ganges. It's important to approach such claims cautiously and base discussions on scientific evidence and information from reputable sources.