You can go for 4 days,6days,7dqys or 12-15 days(if you also want to visit Badrinath,Kedarnath,kausani,Haridwar) It depends on you how many places you want to cover but according to me you should take atleast 7 days.
You can spend time in Nainital,Sattal,Corbett,Mussoorie.
How many days is totally depended on you. but the it shall not take more than 7 to 8 days to cover the area things to see in Uttarakhand:- valley of flowers national park yamunotri Nanda Devi badrinath temple tungnath nainital lake
Hi Neelam, if you are looking to cover the tourist destinations of Uttarakhand 7-8 days would be sufficient for you. Your itinerary can cover Haridwar, Rishikesh, Dehradun, Mussorie, Joshimath, Auli. Auli is the best place for skiing in India and you will really enjoy the experience if you are visiting in Winters! #happytripping