jigar,
As the others have said, there are LOTS of Itinerary possibilities for your trip. While it might be theoretically feasible to include the Greek Islands, IMHO it would complicate things due to the travel times.
Given the circumstances with your flights, you might consider something along these lines:
Fly to Paris (You may lose a day in flight times - you didn't say where you're located - where is Patel?).
Tour Paris - 5 days? (one day for day trip to Versailles or elsewhere if desired)
Train to Amsterdam-3 days?
Budget flight to London-5 days? (one day for day trip to Bath or elsewhere if desired)
Budget flight to Rome-5 days? (allowing one day for day trip if desired or spend time in Rome - LOTS of sites to see!)
Train to Cinque Terre, Florence or other location in northern Italy-3 days?
Train to Switzerland-3 days? (would you prefer cities in Switzerland or the more "traditional" Switzerland? One big favourite here is the Berner Oberland region and especially the small villages of Gimmelwald or Murren - you could perhaps visit two locations in Switzerland depending on your priorities)
Train to ??? -3 or 4 days(at this point, the goal is to get back to Paris in time for your flight - you could either visit the Black Forest area of Germany or the Alsace/eastern region of France.
Train to Paris - 1 night (pre-book your Hotel - ask your Hotel to reserve a Shuttle to Paris/CDG for the following day.
Keep in mind that some travel days of ~6 hours or so will be a factor in some of the train trips I've listed. For the budget flights, PACK LIGHT or you'll get "nicked" with an overweight charge!
This is only one suggested Itinerary. I'd suggest picking up a copy of Europe Through The Back Door, as that has an incredible amount of information not only for trip planning but also for travelling smartly in Europe.
Good luck and Happy Travels!
