Read content control in word using office js apps
is there any option to read/write content control from word 2013 using office Apps(office Add-in) or office.js API's
Yes, in Word 2013 content control access is available through the Bindings API (MSDN documentation link). The main limitation in Office 2013 (solved in Office 2016) is that you must rely on the user to indicate which content control should be bound based on her selection. Good UI design in your task pane will ensure that choosing which content controls to read/write from is seamless and intuitive.
If you'd like to give Word 2016 users an even-richer experience with content controls, then I would recommend that you also make use of the Content Control object.
-Michael (program manager for add-ins)