How to disable (hide) specific Export Button from RDLC ReportViewer in ASP.Net

1. Add OnLoad event handler to the ReportViewer.

 OnLoad = "ReportViewer_OnLoad"

2. And the use the following code

protected void ReportViewer_OnLoad(object sender, EventArgs e)
{
    RenderingExtension extension = ReportViewer1.LocalReport.ListRenderingExtensions().ToList().Find(x => x.Name.Equals("Excel", StringComparison.CurrentCultureIgnoreCase));
    System.Reflection.FieldInfo info = extension.GetType().GetField("m_isVisible", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
    info.SetValue(extension, false);
}

Please refer this article

ASP.Net RDLC (Local SSRS) Report Viewer: Hide (Disable) specific export option (Word / Excel / PDF) from Export button