Creating Templates

Not sure what you mean...Appian allows you to design your own interfaces which can take inputs and use those inputs to render the interface, so in effect SAIL Interfaces are templates.Could you clarify what you're looking for or trying to achieve?

Can we create our own templates like displayed in picture in appian??Not using the existing one creating new one ...

You can't create a template that gets added to this existing list in Interface Designer. However, like Stewart said, all interfaces can be reused inside of another interface by calling rule!<Your Interface Name>.

I often create a shared application in my environment with templates and helper interface rules that can be used in any application. Then, you should be able to easily reuse the interface in any other interface as necessary!