GST on supply of bus service

XYZ(Proprietor) supplying Bus service to PQR Pvt.Ltd. for transporting their employees from factory to nearby destinations. In the month of January’21, XYZ crossed the threshold limit of Rs.20 Lacs from this business. 1) Whether XYZ is required to register with GST and pay GST under forward charge or 2) PQR was required to pay GST under reverse charge?