Hey Ashutosh, Here are few off beat destinations that you can cover in 12 days : Dharmshala and Mcleodganj in himachal pradesh Rishikesh and haridwar in uttarakhand ... go on water rafting and bungee jumping here ... Go to bir billing in himachal for pata gliding Go to dehradun and explore the himalay ranges ... go to munsiyari in Uttarakhand jibhi in himachal Pradesh tosh Village in malana in himachal Pradesh Happy Travelling Bro!!!
Then u can plan to stay in one state for 6 days ... cover the destinations which u need to visit and then move to next .. both states are having good public transport system .. or else hire a bike in pathankot and just ride to all of them .. u will intact enjoy the trip more in that way ...
If you are planning to start you HP trip from Pathankot, Dalhousie and Khajjiar will be the nearest attractions. The go towards McLeod (Triund trek will be lovely now), Bir Billing. Later you can go to Chitkul if you want to travel extensively. Chitkul is last indian billagebon Indo Tibet border and will be capped with snow now. Later you can try a Jibhi and Gursaini and end you trip there.
Hey Ashutosh, You can go to Dharamshala and Dalhousie from Pathankot. This is my itinerary of Dharamshala : https://www.tripoto.com/trip/four-day-itinerary-of-dharamshala-5bbf6eb477505?ref=mobwapp&source=awp Go to Dalhousie after covering Dharamshala. Places to visit in Dalhousie : 1)St. Patrick's Church 2)Subhash Baoli 3)Bara Pathar Temple 4)Chamba 5)Khajjiar 6)Laxmi Narayan Temple 7)St. John's church 8)Norwood Paramdham fro sunset Hopw this would help you. Happy travelling!!!!!!
Routes to Spiti valley during Jan aren't favorable to travel. Kaza and near by places were an option for us but we found there are almost no routes to there from Manali.