Hey Soumyajett,
In December you can get snowfall in north and northeast India like
1)Manali
2)Shimla
3)Gangtok
4)Tawang (Arunachal Pradesh)
5)Mussorrie
If you are living near Delhi then go to Mussorie (Uttrakhand).If near Chandigarh go to Manali.
If near Siliguri then go to Gangtok.
Spiti its already there and temperature is touching -7 -8 already
kashmir is having snow
this year the chances are very high of good snow fall early on high altitude places