Is there any way to load old image (21.4, not 21.5) on TK1?

There is no default binary image. The default is flashing with the R21.4 sample rootfs (don’t forget the apply_binaries.sh step and don’t forget to use sudo for this and unpack of sample rootfs). So look for the R21.4 driver package, and use the R21.4 sample rootfs from the same download page with that to get R21.4. The image will be generated.