
When I'm clicking on Install Repository and sync project link then nothing happens.

When I'm clicking on Install Repository and sync project link then nothing happens.
You need to add this:
maven { url "https://maven.google.com" }
to project level build.gradle file look like this:
allprojects {
repositories {
jcenter()
maven { url "https://maven.google.com" }
}
}
The support libraries are now available through Google's Maven repository. We no longer support downloading the libraries through the SDK Manager, and that functionality will be removed soon.
More details see here.
Edit: Also update your support library versions to 26.0.1 along with compileSdkVersion to 26 and buildToolsVersion to 26.0.1
Have you put this line in your app level gradle file? classpath 'com.google.gms:google-services:3.0.0'