[SapnaVishwas]

Here is the code, just dont copy paste and submit your project. Try to understand how i implemented, if possible use your own approach and take this code as reference.
MovieStore.java

import java.util.ArrayList;

public class MovieStore {
   // Add the missing implementation to this class

   /* You need a dynamic structure to keep movies in store */
   /* ArrayList is a dynamic array which you can add or remove item easily */

   private ArrayList<Movie> store = new ArrayList<Movie>();
   public String storeCity = "";

   public MovieStore(String city){
      storeCity = city;
   }

   public static String printOpeningHours(){
      return "Open daily from 9am to 5pm.";
   }

   public void addMovie(Movie m){
      store.add(m);
   }

   public String printMovieStoreCity(){
      return storeCity;
   }

   public String borrowMovie(String movieName) {
      // Check whether we have the movie
      Movie temp = null; // We set movie object to null if we cant find movie it will be still null after loop
      for (int i = 0; i < store.size(); i++) {
         temp = store.get(i);
         if (temp.getTitle().equals(movieName)){
            break; // we found the movie quit loop and assign movie object to temp.
         }
      }
      
      String returnMessage = "";
      
      if (temp == null){
         // That means we dont have movie in the store
         returnMessage = ": Sorry, " + movieName + " is not in our catalog. ";
      }
      
      if (temp != null){
         // yay we have the movie
         // Lets check if it is already borrowed.
         if (temp.isBorrowed() == true){
            returnMessage = ": Sorry, " + movieName + "is already borrowed.";
         }else{
            // Available for borrow and lets borrow it
            temp.borrowMovie();
            returnMessage = ": You successfully borrowed " + movieName;      
         }
      }
      return returnMessage;
   }

   public String printAvailableMovies() {
      // Create a string for output.
      String movieList = "";
      for (int i = 0; i < store.size(); i++) {
         Movie temp  = store.get(i);
         if (!temp.isBorrowed()){
            movieList = movieList + temp.getTitle() + "\n";
         }
      }
      return movieList;
   }

   public String returnMovie(String movieName) {
      // Loop through store array and when you find movie, call it's returnMovie fuction
      for (int i = 0; i < store.size(); i++) {
         Movie temp = store.get(i);
         if (temp.getTitle().equals(movieName)){
            temp.returnMovie();
            break;
         }
      }
      return " You successfully returned " + movieName;
   }
}

Movie.java

public class Movie {
   String title;
   boolean borrowed;

   /*Constructor */
   public Movie(String MovieTitle){
      title = MovieTitle;
   }
   /* Marks the Movie as rented */
   public void borrowMovie () {
      borrowed = true;
   }

   /* Marks the Movie as not rented */
   public void returnMovie () {
      borrowed = false;
   }

   /* Return true if the Movie is rented, false otherwise */
   public boolean isBorrowed() {
      return borrowed;
   }

   /* Return the title of the Movie */
   public String getTitle() {
      return title;
   }
}