The study of confined water molecules is important in chemistry, physics and biology because they are associated in many interface chemistry such as protein, lipid, DNA, etc. Recently, we found that hexagonal phase of modified REPO4 retains water molecules up to very high temperatures. REPO4 (RE=Y, La) is compound having high temperature stability. When ions with higher ionic size (say Bi3+, Ce3+, Eu3+) substitute RE3+ site, one can obtain monoclinic or hexagonal phase depending on synthesis methods. Hexagonal structure have zeolite configuration, in which many pores are available along the c-axis (like a channel). TGA-MS curve shows that hexagonal phase of modified REPO4 (RE=Y, La) retains water molecules up to very high temperatures up to 1073 K. The confined water molecules are not frozen even at 215 K. In order to understand the anomalous behavior of confined water we need to identify the positions/locations and binding state of water molecules. The combined neutron diffraction and quasielastic neutron scattering studies will provide microscopic understanding of the phenomena.