There are 2 ways to reach spiti velly in Himachal Pradesh. one is from the side of manali .. ---- atal tunnel ---- batal ----losar --- kaza (spiti) second one is from Shimla --- reckong pio --- Nabo --tako ---kaza (spiti) roads may be close due to snow. get all your important information prior before going.
Spiti is a mesmerising hill station filled with abundant nature which is a great treat to a travellers eyes. There are a few ways to reach Spiti Via Rohtang pass Gramphu you reach
Another route is via Narkanda Nako If you choose to travel by train from Chandigarh there are lot of trains
One such train leaves from Shimla a toy train. Joginder Nagar station is the nearest station to Spiti. There are regular buses too from Manali, Kullu which reaches Kaza and from there you need to self drive or take a cab to Spiti.
https://www.tripoto.com/trip/how-to-reach-spiti-valley-cheapest-way-to-spiti-valley-delhi-to-spiti-valley-5d2e311b5ad5c
Kindly check the above Tripoto link for more details.