Degrees of Freedom

There are two rotational degrees of motion for diatomic gases because one for each of the two axis perpendicular to the cond between the two atoms

The molecules of diatomic and linear polyatomic gases are made up of two atoms joined rigidly to one another through a bond (such as H₂). Such a molecule cannot only move as a whole but can also rotate about one of the three co-ordinate axes. However its moment of inertia about the axis joining the two atoms is negligible compared to that about the other two axes. Hence it has only 2 rotational motions

swordfish , agreed that both will be similar, but a molecule can rotate about both of these axes simultaneously , so u cant just consider only 1 of them . the KE due to rotation abt both axes will add up
i hope i m clear