Most (if not all) gelatine contains sulfur dioxide as a preservative/biocide (certainly Dr Oetker's does). However most vegetarian gelatine substitutes, such as Dr Oetker's Vege-Gel, do not. (Note: if using a vegetarian gelatine substitute read the instructions, as they sometimes have to be used slightly differently to animal-derived gelatine.)
The presence of sulfur dioxide should be indicated on the label, either as sulfur dioxide, sulphur dioxide, or E220 (at least in North America and the EU and other places with food labeling laws). I'm not sure if the question is because of a particular intolerance to sulfur dioxide or a general desire not to want to eat sulfur dioxide. If you have a serious allergy to sulfur dioxide or any other product you should contact the manufacturer, your doctor, or a properly accredited and registered dietitian/nutritionist, not rely on strangers on the internet for advice.