how to save the resume as a link in gridview and that link should open?

Try code like this in a template column -

<asp:templatecolumn >
  <itemtemplate>
    <asp:hyperlink navigateurl='<%#Eval("url")%>' text="view" runat="server" id="resume path"/>
  </itemtemplate>
</asp:templatecolumn>

If the file is found through the link path, the browser will automatically open the file from that location.