If you are looking to enable the rating feature in your SharePoint.
Below is the script which can help you out with it.
Add-PSSnapin "Microsoft.SharePoint.PowerShell"
$web=Get-SPWeb "http://rahulsp.com";
$list=$web.Lists["Pages"];
if($list -ne $null)
{
Write-Host $list.Title "not null";
$assembly=[System.Reflection.Assembly]::Load("Microsoft.SharePoint.Portal, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c")
$reputationHelper =$assembly.GetType("Microsoft.SharePoint.Portal.ReputationHelper");
$bindings = @("EnableReputation", "NonPublic", "Static");
[System.Reflection.BindingFlags]$flags = [System.Reflection.BindingFlags]::Static -bor [System.Reflection.BindingFlags]::NonPublic;
$methodInfo = $reputationHelper.GetMethod("EnableReputation", $flags);
#For enabling Ratings
$values = @($list, "Ratings", $false);
#OR for enabling Likes
#$values = @($list, "Likes", $false);
$methodInfo.Invoke($null, @($values));
#For disable Rating or Likes
<#$methodInfo = $reputationHelper.GetMethod("DisableReputation", $flags);
$disableValues = @($list); $methodInfo.Invoke($null, @($disableValues));#>
}