You dont need to unistall linux and virtual machine.
You need to create your stage ISO again.
Make sure the stage has only those sub folders that I have pointed out. Some hwere something has gone wrong.
Start by examining the folder where you have downloaded Oracle files. See if you can figure out a problem there.
Recreate the ISO file.
In Linux, remove the "stage" folder and "PROD" folder using rm -r command.
"PROD" folder would have been created if rapid install started the installation. Otherwise it will not be there.
Unzip all files again from the CD into the stage folder.
If you are not comfortable then let me know. I help you in finding out the root cause but it could take some time. I will start by asking you to upload the screen shot of your ISO content.