Hello sir I need to know that what is the effect of adding Google +1 button in websites on the search engine ranking of websites?
Yes, Google+ views plays a significant role in rankings. Google is now considering the popularity of your sites pages on Google+ and accordingly determines the rankings. You may say that it is now one of the factors Google use to determine the rankings.
As Google+ is a program of Google.com so if you use Google + button on your site, then your site would be given higher value in Google search engine.