The example of oligosaccharide is

📌 Concept:
Classification of Carbohydrates
Monosaccharides
Known as simple sugars, which include single sugar units.
Example: Glucose, Fructose, Ribose
Oligosaccharides 
Yield two to ten monosaccharides on hydrolysis.
Example: Sucrose, Maltose
Polysaccharides
Yield a large number of monosaccharides on hydrolysis.
Example: Starch, Cellulose 

✅ Explanation:
Sucrose on hydrolysis gives two monosaccharides called, Glucose and fructose. Hence it comes under Oligosaccharides.