AlumniSushma,
Most likely, TestComplete does not recognize the tab control you are using as a tab control. In this case, it uses clicks with coordinates to simulate use actions. If a control was recognized as a tab control, TestComplete would use the ClickTab method to simulate the tab selection.
Delphi has two standard controls that provide the tab functionality: TPageControl and TTabControl. To reproduce the issue, I created a test application that shows controls of both types in a frame. TestComplete recognized both of these controls as tab controls in that application. So, I suppose that you are using a custom tab control. In this case, it's OK that you don't see individual tabs in the Object Browser (as far as I can see, only the tabs of TPageControl are shown as items in the Object Browser, the tabs of TTabControl are not shown).
To command TestComplete to recognize your control as a tab control, you need to change some settings of your test project:
* Launch your application.
* Switch to the Object Browser and find your tab control there.
* Find the WndClass property on the right and memorize (or write down) its value.
* Switch to the Project Explorer[ panel, right-click your test project there and choose Edit | Properties from the context menu. This will open the project editor and activate the editor's Properties page.
* Select Object Mapping on the left of the page. This will open the Object Mapping settings for editing on the right.
* Choose the Win32 Controls and Windows | Tab control object category and add the class name of your control to the list (see the attached image).
* Select File | Save from the main menu to save the changes.
Now, TestComplete will recognize your control as a tab control and will use the ClickTab method for tab selections.
