Krishan,
one way is simply to use equally spaced points along an interpolation of your original data:
unum = Module[{data, data1, data2, if1, if2, data1i, data2i},
data = Import["C:\\Users\\KRISHAN\\Dropbox\\Journal Drafts\\Draft 4\\Numerical study\\velocity uniform permeability.xlsx"];
data1 = data[[1, 2 ;;, {1, 2}]];
data2 = data[[1, 2 ;;, {1, 3}]];
{if1, if2} = Interpolation /@ {data1, data2};
{data1i, data2i} = Transpose@Table[{{x, if1[x]}, {x, if2[x]}}, {x, 0, 1, .025}];
ListPlot[{data1i, data2i}, PlotStyle -> {{Black, Thick}, {Black, Thick}}]];