There are two routes to reach Banjar (Tirthan Valley) from Delhi/Chandigarh, out of which one is via Shimla. You will cross places like Shoja, Jalori Pass, Jibhi if you choose to drive via Shimla. But it is approximately 50 km extra compared to the other one.
The other route is via Aut tunnel. If you are traveling by your convenience then simply use google map. However, if you go by this route you need to take a detour from the tunnel towards a place called Bali chowki. From Bali chowki again there are two diversions, you can take the left road which goes to Banjar. Except, if you are one like me who prefers public transport over luxury on mountains, then here are a few details -
Bus 1 - Book your ticket in a bus going to Manali or Bhuntar. Get down just before the Aut tunnel or at Aut station.
Bus 2 - Frequency of buses going to Banjar is as scarce as you can imagine. So you can hop onto any bus going towards Bali chowki. If you are lucky enough, you might also get a direct bus till Banjar.
Bus 3 - Get down at Bali chowk and hop on a bus going to Banjar.
Bus 4 - Finally, after 1.5 hours of your journey you will reach Banjar bus stand which is a pretty big one for Himachal.
However, your journey doesn't end here, from Banjar you again need to take a bus going towards Bathad to reach Gushaini. A majority of stay options are set up in Mungla which lies 2 km ahead of Gushaini. Besides, if you are visiting the valley off-season then this place can be all yours!
Places to visit -