From the error message it seems like the version of Xcode (may be an older Xcode) you are trying to install is trying to write something on to the system volume. In macOS Catalina, system volume is read only.
From the error message it seems like the version of Xcode (may be an older Xcode) you are trying to install is trying to write something on to the system volume. In macOS Catalina, system volume is read only.