c# - how to access a list inside a generic object

I have a generic object containing a list with objects, which I like to access. By using

object sourceValue = new List<tab> {new tab()};
PropertyInfo[] sourcePropertyInfo = sourceValue.GetType().GetProperties();
//First field of PropertyInfo is the list, second is a Raw instance
object result = sourcePropertyInfo[0].GetValue(sourceValue, null);

Where the tab object looks like this:

public partial class tab
{
    public long TabId { get; set; }
    public string Title { get; set; }
}

Here I would like to access the list throught the result variable but it results in result = 0, which is an integer. Most likley it takes the count property from the list. How can I access the values in the objects in the list (of type tab)?

Note, I can not access or change the type of the object sourceValue.