The JavaScript equivalent to PHP explode() is split(). To get the data after the first colon, try to run the following code.
Example
<!DOCTYPE html>
<html>
<body>
<script>
var str = '087000764008:Rank:info:result';
var arr = str.split(":");
document.write(arr[1] + ":" + arr[2]);
</script>
</body>
</html>