When you using telerik report old version in your project, Telerik report viewer print button not working chrome new version overcome this problem please used below java script function. This code working properly most popular browsers. For more details

<Script>

$(function () {

            var frame;
            window.telerikReportViewer.printManager.print = function printPdf(src) {

                if (!frame) {
                    frame = document.createElement("IFRAME");
                    frame.style.display = "none";
                }

                frame.src = src;
                document.body.appendChild(frame);

                frame.contentWindow.focus();
                frame.contentWindow.print();
            };

        });

    </script>