When you remove an offset from a clivia you need to include enough roots on the offset for it to be able to live on its own as an adult. If your offset had no roots at all, it's unlikely to survive. If the base of the plant looks healthy, it may grow new roots, but it can take months. Its much more likely to rot. I have gotten rootless clivias to grow new roots by growing them in damp long fiber sphagnum moss. I just set the base of the plant on the moss and propped it to stay in place. It took at least three months for roots to grow long enough (1-3 inches) to put in regular clivia potting mix.