If it is an embedded subtitle, it depends on the embedded subtitle;
If the embedded subtitle overlaps with the picture (that is, there is a picture part in the subtitle background), it cannot be removed, and there is no software to remove it.
If the embedded subtitle does not overlap with the picture (that is, the subtitle background is solid color and there is no picture part), it can be removed, and the subtitle can be covered with a ribbon of the same color.