I was able to fix this. I was missing the file tegra194-mb1-bct-ratchet-p3668.cfg. I saw that a file was missing and the command I ran was sudo ./flash.sh --no-flash jetson-xavier-nx-devkit mmcblk0p1 to generate the file again as mentioned again, and ran this command - sudo ./flash.sh -k secure-os jetson-xavier-nx-devkit mmcblk0p1 again and was able to boot the secure-os successfully.