Two variables? Here are two ways:
\[CapitalLambda] = 0.124913/30;
\[Mu] = 0.0000171;
\[Mu]1 = 0.0003975322;
Plot3D[(\[CapitalLambda] gamma)/(\[Mu] (\[Mu] + \[Epsilon]2 + \[Mu]1)),
{\[Epsilon]2, 0, 0.001}, {gamma, 1, 3}]
Manipulate[
Plot[(\[CapitalLambda] gamma)/
(\[Mu] (\[Mu] + \[Epsilon]2 + \[Mu]1)),
{\[Epsilon]2, -0.001, 0.001}],
{gamma, 1, 3}]