You can check out this itinerary to plan an 11 night & 12 days Char Dham Yatra:
Day 1: Reach Delhi, move towards Haridwar, check-in at the hotel in Haridwar.
Day 2: Reach Barkot, enjoy a stopover in Mussoorie and enjoy at Kempty Falls, check-in at the hotel in Barkot and stay there overnight.
Day 3: Go on a trek to Yamunotri, take a holy dip at the Jamnabai Kund and offer prayers at Divya Shilla, visit Yamunaji.
Day 4: Leave for Uttarkashi, visit Kashi Vishwanath temple en route, leave for Gangnani
Day 5: Enjoy a trek to Gangotri of 5-6 hours, indulge in some holy activities, drive back to Uttarkashi, reach Gangnani/Uttarkashi for the halt and stay there overnight
Day 6: Travel to Sitapur, check-in at the hotel and relax for the day
Day 7: Trek to Kedarnath from the base camp at GauriKund, offer prayers to the deities, reach back to the hotel in Sitapur
Day 8: You can relax for the day in Sitapur, you can also visit Trijugi Narayan
Day 9: Head towards Badrinath Ji, stopover at Joshimath, Narasimha Temple, and Shankaracharya Math on the way to Badrinath
Day 10: Proceed for Srinagar, enjoy your tour to Vishnuprayag, Karnprayag, Nandprayag, Rudraprayag and Devprayag, check-in at the hotel in Srinagar and stay there overnight
Day 11: Move towards Haridwar, visit Rishikesh and Devprayag en route, check-in at the hotel in Haridwar
Day 12: Departure