Open in new Tab or new Window in Selenium Webdriver

New Tab:
Use the below code to complete the action in a new tab.

WebDriver driver = new FirefoxDriver();
driver.get("http://aksahu.blogspot.in/");

You can  do by either of the below ways

driver.findElement(By.linkText("Tips & Tricks")).sendKeys(Keys.CONTROL + "t");

Or

WebElement aLink = driver.findElement(By.linkText("Tips & Tricks"));
Actions actions = new Actions(driver);
actions.moveToElement(aLink);
actions.contextClick(aLink)
       .sendKeys(Keys.ARROW_DOWN)
       .sendKeys(Keys.ENTER).build().perform();

New Window:
Use the below code to complete the action in a new window.

WebDriver driver = new FirefoxDriver();
driver.get("http://aksahu.blogspot.in/");

Open a web page in a new window:

String script = "var d=document,a=d.createElement('a');a.target='_blank';a.href='%s';a.innerHTML='.';d.body.appendChild(a);return a";
Object element = ((JavascriptExecutor) driver).executeScript(String.format(script, "http://aksahu.blogspot.in/"));
if (element instanceof WebElement) {
    WebElement anchor = (WebElement) element;
    anchor.click();
    ((JavascriptExecutor) driver).executeScript("var a=arguments[0];a.parentNode.removeChild(a);", anchor);
} else {
     throw new JavaScriptException(element, "Unable to open Window", 1);
}

Open a link in a new window:

WebElement elemLink = driver.findElement(By.linkText("Web Driver"));
Actions actions = new Actions(driver);
actions.moveToElement(elemLink);
actions.contextClick(elemLink)
       .sendKeys(Keys.ARROW_DOWN)
       .sendKeys(Keys.ARROW_DOWN)
       .sendKeys(Keys.ENTER).build().perform();