Hey @Kritika, you can use Actions class to drag and drop a web element using Selenium Webdriver. dragAndDropBy() method of Actions allows us to drag the element and drop it to a particular location (provided its coordinates). Following test case will drag and drop a box element:
FirefoxProfile profile=new FirefoxProfile();
profile.setEnableNativeEvents(true);
WebDriver driver=new FirefoxDriver(profile);
driver.navigate("http://jqueryui.com/draggable/");
Thread.sleep(6000L);
WebElement element=driver.findElement(By.xpath("//div[@id='draggable']"));
Actions actions=new Actions(driver);
actions.dragAndDropBy(element, 60, 70).build().perform();
}