Thanks you all, who gave me excellent suggestions over my previous post. I did some more reading and came up with two options. One includes flight and another is via train. I am considering, which option looks more feasible and economical for us (we are 2)
BY FLIGHT -
Day-1: Reach Paris at 11:30 AM. Flight to Geneva at 16:00-15:10. Take train towards Murren.(Flight cost $110 for both of us)
Day-2: Trummelbach Falls, Brienz, Lake Lucerne, Engelberg and other nearby areas and come back to Murren for night. If time left, may be Mt.Titlis.
Day-3: Take the train up to Wengen, walk around, ride the cable car up (straight up) to Manninchen, walk trail to Kleine Scheidegg. Then take the train down to Grindelwald and return to Murren by evening.
Day-4: Leave hotel, Lake Thun, Spiez, Bank of the Rhine, Marktplatz, Basel. Spend some time till evening and then take flight in evening from Basel to Paris. (Flight cost $110 for both of us)
Day-5: Full day Paris and nearby attractions. Will commute all by train
Day-6: Leave hotel in morning and fly out Paris airport.
BY TRAIN -
Day-1: Reach Paris at 11:30 AM. Take train till Murren (TGV+other trains). It will be night by that time, so just stay in hotel.
Day-2: Trummelbach Falls, Brienz, Lake Lucerne, Engelberg and other nearby areas and come back to Murren for night. If time left, may be Mt.Titlis.
Day-3: Take the train up to Wengen, walk around, ride the cable car up (straight up) to Manninchen, walk trail to Kleine Scheidegg. Then take the train down to Grindelwald and return to Murren by evening.
Day-4: I have two options here -
a) Leave hotel, Lake Thun, Spiez, Bank of the Rhine, Marktplatz, Basel. Later leave for Paris in evening.
b) Leave early from hotel. Leave for Montreux/Lausanne. Spend some time till evening and then leave for Paris.
Day-5: Full day Paris and nearby attractions. Will commute all by train
Day-6: Leave hotel in morning and fly out Paris airport
If any changes are needed, please suggest.