In 6 days you can include Manali, Salong Valley ,Kasol, Rohtang Pass, Chandratal Lake.(Best himalayan experience) Or In 6 days you can do, Shimla, Chitkul. or You can do, Khajjar, Bir Billing , Dharamshala, Mcleodganj , Triund Trek. (Suggested)
Hi keshav , i ll suggest u to visit dharmshala , mcleodganj , dharmkot , bir-billing, dalhousie , khajjiar and surrounding areas. you ll have lots of fun. and if u want 2nd option then u can go to kasol , jibhi , manikarn and surrounding areas. they are peaceful and awesome locations.
It depends on the kind of trip you would want to have. If you want to just go, chill and sit beside river and enjoy food. I would suggest you to visit Old Manali. The weather is amazing there, temp reaches to almost 4-5 degree in the night. Spend 3 days there and then 2 days at Kasol. Both these places would be really good. on the other hand if you want to experience adventure then I would suggest you to visit McLeodganj(Dharamshala) and do triund trek. From there you can visit Bir and can enjoy Paragliding.
Okay so go to kasol, malana, waichin valley, solang valley, bir billing, rohtang pass. You can cover it in 6 days and ask the locals about the directions because they know everything about the surroundings..