Tellin.js uses Ejs as the template. You can find some more detail about Ejs from its website.

Where to put template files

You can put the template folder in the folder '_view'.

Also you can change the default root folder in tellin.config ('_Path_ViewFolder').

Ejs controls

Here is a part of tellin.json.

//...
"filename":"./_view/controls",
//..

The filename is required by ejs.js. You can put your ejs controllers there.