For kasol you will need to go Rishikesh and for rohtang pass you have to go manali
day1- Manali local sight seeing rent a hotel day2- Woke up early because rohtang pass is traffic prone area. After 15sep you are not going to get a bus to rohtang pass because of heavy rainfall so you have to rent a car.
day3- Manali to shimla local sight seeing. Mall road and all.
day4- Shimla to rekong peo it around 200km away but a must visit site. May be you will get a bus if you will stay woke up early.
day5- rekong peo to kalpa take a rest enjoy beauty of Kinnaur Kailash a Holy peak.
Day6- Kalpa to Chitkul (the last village of india) must visit.
day7- chitkul to narkanda it is on the way back to Shimla.
then look for kasol
Rest in Chd if you land in evening
Start your journey in the morning to kasol, you can go for Tosh valley & Manikaran, it'll take you 2 days and one night
Then move for kullu, trek to bijli mahadev temple and then go for Manali same day, rest and explore manali, Gulaba Valley, Solang Valley and Rohtang Pass. It'll take you around 3-4 days.
Hey.. start your journey from Chandigarh to Shimla... stay for 2 days cover all local places thn travel to Kullu.. Kasol.. Kheerganga.. Tosh.. depends on your preferences... and Thn Manali.. you would be able to cover all major chunks of these beautiful places...Also would suggest try hostels instead of hotels it would be a good experience... have a safe trip
From Chandigarh, head over to Kalka, board the toy train for Shimla... Enjoy the UNESCO World Heritage rail route. Day 2-3: Explore Shimla and Kufri, take overnight bus to Kasol. Day 4-5 : Explore Kasol Day 6-7 : Explore Manali and Rohtang pass Day 8 : take a bus back to Chandigarh... DM for any further information and assistance...