Hi, Both option are suitable however taking a Bus from Shimla to Manali (Kullu) is budget friendly. AC bus services operating between Shimla & Manali by HRTC so it will be a good idea. From Narkanda to reach Shimla you can avail any share taxi or cabs operating daily. Hiring cabs will cost you around 5k+ one way however BUS will cost max 1k . So you can take decision according to your need. Timing will not vary much Cab may take 5-6 hours where as Bus may take additional 2 hours. Hope above information will help in planning your next road trip Thank You See You on the Road...👌👌
Sreya, you can take a cab visit narkanda. There is an HP tourism hotel in Narkanda stay there the night. The next morning you can go to kullu via rampur and Jalori pass. It's a small road and will take time, however if you haven't been there it's a very pretty way