Yes, if ΔPQR≅ΔEDF, then it means that corresponding angles and their sides are equal because we know that, two triangles are congruent if the sides and angles of one triangle are equal to the corresponding sides and angles of other triangle.
Here ΔPQR=ΔEDF.
∴PQ=ED,QR=DF and PR =EF.
Hence, it is true to say that PR =EF.