Not clear.. Where is the template residing ? Has somebody created a template ?
The template already provided in PDF and Word format files.
just I want to print out OR export tableau file (sheet/dashboard) on the template I provided.
I suppose you could use an image file (jpeg or png) of your template as a background image in your dashboards. Tableau doesn't support what you're describing. It's an interactive tool, so static templates aren't really something that's concentrated on.
As mentioned, you won't find a way to automatically place your visualization into your custom/template PDF/PowerPoint.
What you can do is go to the Worksheet menu option, choose Copy, and then paste it into your PDF editing tool or Word to produce whatever export you want. There is no current way to automatically direct an export into another document, as again, Tableau is a tool built for visual interaction (and usually, once we leave Tableau for a PDF or PPT are are then looking at a "photo"/screenshot of the viz -- not the actual viz itself.