test.css

body {
    padding-top: 50px;
    padding-bottom: 223px;
    background-image: url(/content/images/abc.png); background-image: url(/content/images/abc.png);
}

.div1 {
    background-image: url(/content/images/abc.png);
}

.div2 {
    background-image: url(/content/images/abc.png);
}

.div3 {
    background-image: url("/content/images/abc.png");
}

.div4 {
    background-image: url("/content/images/abc.png");
}

.div5 {
    background-image: url("/content/images/abc.png");
}

.div6 {
    background-image: url("/content/images/content/abc.png");
}

.div7 {
    background-image: url(/content/images/content/abc.png);
}

web.config

<rewrite>
  <outboundRules>
    <rule name="RewriteCSS" preCondition="ResponseIsCss">
      <match filterByTags="None" pattern="/content/([^&quot;\)]*)" />
      <action type="Rewrite" value="/replacedcontents19/{R:1}" />
    </rule>
    <preConditions>
      <preCondition name="ResponseIsCss">
        <add input="{RESPONSE_CONTENT_TYPE}" pattern="^text/css" />
      </preCondition>
    </preConditions>
  </outboundRules>
</rewrite>