I started with differentiation of all three coordinates of this parametrically given curve.
I want to show that the respective curve has related equation of the plane and also to prove that it a "plane-curve".
$$\gamma\left(t\right)=\left(\frac{1+t^2}t\;,\;{t+1}\;,\;\frac{1-t}t\right)$$
Hint: Show that torsion is null. You can see the formules here.