Can we use Selenium webdriver for automating MS CRM 2015 based application?If not, is there any specific reason for that.
Selenium can automate any part of a web page if it is based on HTML. So if you want to check it, open the CRM web application, open the browser console and confirm if all the elements required for your automation test are based on HTML.
The non-HTML components of a web page cannot be accessed by Selenium. You might want to use Image Based testing tools like Sikuli.