Hey @Sradha, 
As you have created an array of keywords and you want to search it in a random way. You can use normal script for searching in google and induce your array and pass your elements in a random manner using .random function. Again you can create an array of index of those key words. That's all.
Here is a code for doing that:-
import java.util.Random;
import org.openqa.selenium.By;
import org.openqa.selenium.Keys;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
public class SerachRandom 
{
    public static void main(String[] args) throws InterruptedException 
    {
        System.setProperty("webdriver.chrome.driver","C:\\Users\\Nabarupa\\chromedriver.exe");
        String str[] = {"Hello World", 
        "India","Earth","Asia","Community","Selenium"}
        try{
            WebDriver driver=new ChromeDriver();
            driver.get("https://www.google.com");
            int j[] = {0,1,2,3,4,5};
            Random generator = new Random();
            int randomIndex = generator.nextInt(j.length);
            int k = j[randomIndex];
            driver.findElement(By.name("q")).sendKeys(str[k],Keys.ENTER);
            Thread.sleep(5000);
            driver.close();
            }
       catch(Exception e)
       {
            System.out.println(e);
       }
    }
}
Hope this helps.