Yes, you can fix your fishnet stockings. But you need to be cautious. To fix it, focus on the center of the hole. Now attach it to the top and tie a few more stitches. Remember not to overdo the stitching to avoid getting a bunched knot.
A woolly nylon thread works best for this purpose. Please don’t use a regular needle as it will ruin the fibers. It would help if you sewed these tights with a ballpoint sewing needle.