If it is not categorically stated on the label of medicine by the manufacturer one has to assume that gelatin is used for making capsule. Gelatin is an animal product (non-vegetarian). And it is manufactured from collagen, a fibrous substance that joins bones, cartilage and tendon (tissues that join muscles to bones) of cattle like cows and buffaloes. Some glycerin is added to make the capsule soft.
Another use of gelatin is in making jelly with which a scoop of ice-cream is sometimes ‘topped’, although many people are not aware of it. However, it is a different matter if the label states that jelly is made from vegetable products. This type of notice should be made compulsory by the government in case of bakery products also.
Capsule (pharmacy) (Wikipedia)