Hi, Tushar!
Though there might not be many frequent direct bus services between Shimla and Mcleod Ganj, there are enough buses to Dharamshala, which is just 10 km from Mcleod Ganj. You can check out the following link to know more about the bus timings from Shimla to Dharamshala: https://online.hrtchp.com/oprs-web/avail/services.do
If you're interested in travel in Thailand you might want to try Tour bus It is the best way if not in a rush and want to enjoy the nature, Because it very easy and convenience. When I want to travel in Thailand I use Tour bus all the time. And I always make a booking online . You can save your spot by checking their website for available buses. https://busx.com/en-us