You can find two ways to do this below:
1. Go to File > Properties > File Properties. This will display a list of current file's properties. You can find the version of Corona which was used when the file was last saved under "Render Name". (e.g. Render Name = Corona 8).
2. Run the following script:
for i=1 to (fileProperties.getItems "Render Data").count as integer do (
if ((findstring (fileProperties.getItems "Render Data")[i] "Renderer Name") !=undefined) do (
message=(fileProperties.getItems "Render Data")[i]
if (autosave.Enable==true) do (
message+="\r\n\r\nNote: Auto backup is enabled, this information may be no longer valid after first autosave."
)
messageBox message title:"Renderer information of this file:"
)
)
This will display the same information as the first method.