Hi Krishna,
To fire the rule when there is a cookie exists using Adobe DTM,
Please modify BOLD text from the below JS code as per your requirement and post in the "Customize Page Code" editor and also tick the Check box for Enable EU compliance for Adobe Analytics from the General settings
var loadRule = true;
var ck = getCookie('cookiename');
if(ck=='cookievalue'){
loadRule = false;
}
return loadRule;
function getCookie(cname) {
var name = cname + "=";
var decodedCookie = decodeURIComponent(document.cookie);
var ca = decodedCookie.split(';');
for(var i = 0; i <ca.length; i++) {
var c = ca[i];
while (c.charAt(0) == ' ') {
c = c.substring(1);
}
if (c.indexOf(name) == 0) {
return c.substring(name.length, c.length);
}
}
return "";
}
Refer the screen shots below



Hope this helps
Regards,
Kumararaja K