Planning my trip to Swiss -Suggestions required...

Hi Kiran! First of all, I think you should use the timetable. This helps you to find out which trips are doable in one day and what the specific routes are. A map, such as maps.search.ch, helps you to locate your day trip destinations. As for your specific questions: you will manage to visit the Jungfraujoch after arrival in Interlaken, but you should only do so if weather is still good. The Schilthorn can be very well visited from Interlaken; it can be found in the timetable as well. You can add a visit to Mürren, Lauterbrunnen and the Trümmelbach falls. All three viewing points near Lucerne (Pilatus is closest to the town) are great. They can be combined with a boat trip over lake Lucerne and/or a visit to the old town. You can easily spend another day in Lucerne, but if a larger city has your interest, you can of course choose to get to Zurich.

If you want to stay close to the airport to catch your flight on September 17, you may appreciate the hotel overview for Zurich airport.