Depends upon you brother... On your travel.. accomodation.. and eateries... you can stay at hotels which will cost you more . and if you can stay at hostels.. it will be cheaper... so a trip can be as minimum as you want.
See this is a very open ended question, as it depends upon various factors like form where you are starting your trip and to where in Uttarakhand you are going. However for more clarity you can be place specific to know the answer better
If u want to cover d major tourist places of Uttarakhand like Rishikesh, Nainital, Dehradun etc & involve in activities,ur budget Shud b sumwhere around 10-12k atleast for 4-5days trip which includes transport, accommodation & food