Hi Saurabh,
Thank you for your interest in Syncfusion Products.
Inspite of using a Button that is derived from System.Windows.Forms.Button as a template, you can WebControl button as this button would generate the HTML properly. Please refer the sample below which illustrates the WebControl button as a template to Grid.
http://websamples.syncfusion.com/samples/Grid.Web/6.4.0.15/F78882_AddingBtnTemplate/main.htmPlease let me know if you have any other concerns.
Thanks,
Rekha