When you activate Google Plus comments through Blogger settings, Google+ comment will display automatically bottom of your blog posts. However with some blogger templates, you need to do a little modification to display Google+ comments.
First, confirm that you have activated Google Plus comments.
https://www.blogger.com/blogger.g?blogID=6450127957044146375#googleplus
Now go to "Edit HTML" of your blog.
https://www.blogger.com/blogger.g?blogID=YOUR_BLOG_ID#templatehtml
Find this code block (In your template, you can see this code 2 times):
<b:if cond='data:blog.pageType == "static_page"'> <b:if cond='data:post.showThreadedComments'> <b:include data='post' name='threaded_comments'/> <b:else/> <b:include data='post' name='comments'/> </b:if> </b:if> <b:if cond='data:blog.pageType == "item"'> <b:if cond='data:post.showThreadedComments'> <b:include data='post' name='threaded_comments'/> <b:else/> <b:include data='post' name='comments'/> </b:if> </b:if>
Replace above code with below the code below (you need 2 replace both codes you found in your template):
<b:if cond='data:blog.pageType == "static_page"'> <b:include data='post' name='comment_picker'/> </b:if> <b:if cond='data:blog.pageType == "item"'> <b:include data='post' name='comment_picker'/> </b:if>
Save your template. Now Google+ comments / comments form should be displayed on your site.