Hi Hemang,
You cannot insert form elements in an HTML instance and have them work.There is a limitation to one HTML form per page in ASP.NET and that form already exists so adding another one will likely cause errors on your page and will not work.
We have the Form Wizard Pro add-on which will allow you to create custom forms and use the submitted data to populate database tables or anything else you can dream up by using what we call a "Form Submission Event Handler".
Thanks,
Joe D.