Statements :
a) In translatory motion each point of the body experiences the same displacement as any other point as time goes on, so that the motion of any particle represents the motion of the whole body.
b) In rotatory motion, all the particles in the rigid body moves in concentric circles  about the axis of rotation.

In pure translatory motion, displacement of all particles of the body are parallel and the particles do not move relative to each other.

In pure rotational motion, the axis of rotation is fixed and the particles, lying on the axis of rotation do not move. All other particles move in concentric circular paths of different radii relative to the axis of rotation .

Hence statements (a) and (b), both are correct.