UITableView delegate datasource not set when added from xib using custom UITableView subclass

I have created an application in which I have a subclass of UITableView which gives me custom tableView to add as a header. Initially I am creating this header and adding it programmatically to my UIViewController which is working properly with expected outcome.

Now, I have added a UITableView to UIViewController from xib and changed its class to my header tableView class. When I run this I get blank tableView.

I have assigned delegate and datasource in initWithFrame method of header tableView class(subclass of UITableView)

Can anyone please help me how can I accomplish this with xib?