In the diagram given below what is the direction of friction if the body is in pure rotational motion?

Up the incline

For pure rolling the speed of centre at any instant should be the radius times its angular speed.

$ V = \omega R$

While going down the incline speed is continuously increasing, so its linear & angular speed will be increasing. Friction will provide the necessary torque required for increasing angular speed.

Thus, friction will act upwards so that its torque about the centre will cause the angular speed to increase in the clockwise direction.