Hi Waghmare,

For reading Excel i have used ClosedXML Library. Refer below link for details.

Read and Import Excel data to DataTable using ClosedXml in ASP.Net with C# and VB.Net

Check this example. Now please take its reference and correct your code.

HTML

<asp:TextBox runat="server" ID="txtSearchTerm" />
<asp:Button Text="Search" runat="server" OnClick="Search" /><br />
<asp:Label ID="lblText" runat="server" />

Namespaces

C#

using ClosedXML.Excel;

VB.Net

Imports ClosedXML.Excel

Code

C#

protected void Search(object sender, EventArgs e)
{
    string filePath = Server.MapPath("~/Files/Excel.xlsx");
    using (XLWorkbook workBook = new XLWorkbook(filePath))
    {
        // Read the first Sheet from Excel file.
        IXLWorksheet workSheet = workBook.Worksheet(1);
        // Loop through the Worksheet rows.
        foreach (IXLRow row in workSheet.Rows())
        {
            // Loop through the cells of each row.
            foreach (IXLCell cell in row.Cells())
            {
                if (cell.Value.ToString().ToLower().Contains(txtSearchTerm.Text.ToLower().Trim()))
                {
                    lblText.Text = "Text Found";
                    return;
                }
            }
        }
    }
}

VB.Net

Protected Sub Search(ByVal sender As Object, ByVal e As EventArgs)
    Dim filePath As String = Server.MapPath("~/Files/Excel.xlsx")
    ' Read the first Sheet from Excel file.
    Using workBook As XLWorkbook = New XLWorkbook(filePath)
        Dim workSheet As IXLWorksheet = workBook.Worksheet(1)
        ' Loop through the Worksheet rows.
        For Each row As IXLRow In workSheet.Rows()
            ' Loop through the cells of each row.
            For Each cell As IXLCell In row.Cells()
                If cell.Value.ToString().ToLower().Contains(txtSearchTerm.Text.ToLower().Trim()) Then
                    lblText.Text = "Text Found"
                    Return
                End If
            Next
        Next
    End Using
End Sub

Screenshot