How can components of a packaged food item exceed the net weight? In some packaged foods, the added weight of its components (like sugar, protein, carbohydrates) exceed the weight of the total item.

Example:- 1 pack of Chocos Cereal has net weight 30g. But its components like Total Carbs + Sugar + Protein exceed the net weight of 30g. 

How can the component's weight exceed the net weight of the item?
As Zanna said, you can't just add all the values together, some items are a fraction of others.
In this case, "total carbohydrates" already includes the "sugar" and "dietary fibre" items, so the total is "fat" + "total carbohydrates" + "protein", which adds up to 27g out of 30g. That leaves 3 g for water, ash (inorganic salts, like table salt, basically) and minor components (like vitamins). 

But keep in mind that all those values are rounded to the nearest whole number, which causes the energy stated to be different from that obtained from the ingredients weights.