I am planning a 15 day Europe trip in last 2 weeks of June. Rome will be my start and end point. We are planning to visit Italy, Spain, France, Amsterdam, Switzerland, and Austria. What is a possible itinerary listing all the places that we can visit?

Get the eurail pass, that will allow you to save alot on transport. It will allow you to save on accommodation as you can take the overnight trains. I will suggest that you cut d0wn on a couple of countries, as 6 countries in 15 days is a really tight squeeze, especially as there are alot of amazing sights to visit in each country! Since you don't have much time, you may want to consider taking some tours. When I backpacked across Europe, I took tours from this tour guide market place called http://Mekomy.com. I had a really great time, and visited many cool sights that are not the typical tourist spots and that I would not have found on my own. All the best for your trip, and have fun in Europe!