The quantity of water in one hectare centimeter will be

A hectare centimeter describes the volume of water covering an area of 1 hectare ($10,000{\text{m}}^2$) to a depth of $1\text{cm}$ ($0.01\text{m}$).
$$\text{Volume}=10,000{\text{m}}^2\times 0.01\text{m}=100{\text{m}}^3$$
Since $1{\text{m}}^3=1,000\text{litres}$:
$$\text{Volume in Litres}=100\times 1,000=100,000\text{litres}$$