LaNi5In, NdNi5In and CeNi5In reversible hydrogen absorbers were hydrogenated at room temperature under hydrogen pressure up to 10.0 MPa, forming LaNi5InH1.8, NdNi5InH0.9 and CeNi5InH0.8 hydrides. These were characterised by X-ray diffraction. These hydrides have the same crystal structure as original metal matrix with slightly expanded unit cell (Delta a/a(0) = (0.4-0.8)%; Delta c/c(0) = (0.6-1.2)%; Delta V/V-0 = (1.4-2.8)%. Isotherms of hydrogen absorption-desorption in LaNi5In-H systems were measured at 292.0, 328.5 and 355.5 K. Enthalpy change for reaction with hydrogen was determined. The values Delta H = -(35.9 +/- 2.2) kJ/(mole H-2) on formation of the hydride and Delta H = (33.2 +/- 1.6) kJ/(mole H-2) on reverse transition were obtained. The RNi4In (R = Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) do not interact with hydrogen under the above conditions. Catalytic influence of RNi5In phase on hydrogenation of the RNi4In phase was observed in the case of Pr-containing compounds.