Hey Rushikesh! The Destinations are Amazing with the Classic 350 but you won't be able to enjoy anything apart from the Ride, If Planning it for 6 Days. Would advise 10-12 Days to Enjoy this Roads as well as the Destinations Selected.
Looks like you are on tight schedule with that 6 days Here is the best road map:
Day 1 - Pune to Goa (over night in Goa)
Day 2 - Wake up to the beaches in Goa, I would suggest to stay some place in South Goa, less crowded and calm, its more relaxing - check out a good hostel option to stay would recommend (Palolem), spend a lazy morning and afternoon in Goa and then depart from Goa around 2PM
Day 2 - Goa to Karwar (overnight in Karwar)
Checkout Nirmit Park for unique stya experience in Karwar
Day 3 - Karwar to Udupi (overnight in Udupi)
Explore some food options in Udupi
Day 4 - Udupi to Kannur (overnight in Kannur)
I don't think with the number of days you can go any further than Kannur, you can explore beach side in Kannur and explore the food options here, Kannur is famous for its seafood and Thalasherry Biriyani
Day 5 - Kannur to Bangalore (Overnight in Bangalore)
Explore city life and pubs in Bangalore
Day 6 - Bangalore to Pune Let me know if you have any questions or need assistance