you can do it using template column as shown below :
<asp:GridView runat="server" ID="gridMain" AutoGenerateColumns="False">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<div title='<%#Eval("StudentName") %>'>
<%#Eval("StudentName") %>
</div>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>