new tab

For example,

function newtab()
{
    var browser = Sys.Browser("chrome");
    browser.Page("*").Keys("^t");
    var page = browser.ToUrl("https://support.smartbear.com/testcomplete/");
}

You need to give instructions to TC, as to what URL you want to load

There are a few different ways to open a link in a new tab the way rraghvagni explained is the way that I also use. but depending on the programming language and framework you are using. In TestComplete, you can open a link in a new tab using the following method:

Alternatively, you can use the .click() method on the link element and set the 'ctrl' property to true:

link.Object.click(1, 1, {ctrl: true});

You can also use the right-click context menu option to open a link in a new tab, by simulating a right-click on the link element and selecting the "Open Link in New Tab" option.

Example:

link.Object.rightClick()
Aliases.browser.popupMenu("Open Link in New Tab").click()

You can also use the JavaScript inbuilt function window.open("link","_blank") to open the link in new tab.

Example:

link.Object.eval("window.open(this.href,'_blank');")

Please note that you need to be careful while using the above JavaScript functions as they may be blocked by the browser.

ḥari how would you do this manually?

Alternative solutions are provided by KB1 

See Click Action

Using TestObj.Click(1, 1, skCtrl) will open the link in a new tab, whereas TestObj.Click(1, 1, skShift) will open the link in a new window.