How can I access NavigationController inside UITableviewSource class??

I WANT TO NAVIGATE TO DIFFERENT UIVIEWController on row selected.

I am using UIVIEWController to show the UITableview..

I am not able to access Navigation controller inside this class.

public class RootTableSource : UITableViewSource { UIViewController parentController; IList tableItems; string cellIdentifier = "UIViewController";

    ReportsList reportList;
    AddNewReport addnewReport;

    public RootTableSource(UIViewController parentController)
    {
        this.parentController = parentController;

    }

    public RootTableSource (IEnumerable<VendorDetails> items)
    {

        tableItems = items.ToList (); 
    }


    public override void RowSelected (UITableView tableView, NSIndexPath indexPath)
    {
    // I want to redirect to another UIVIEWController Eg.AddNewReport addnewReport; on row selected 


    }

}