The Himachal Roadways Transport Corporation (HRTC) tops all other states when it comes to online ticket booking and cancellation facilities. HRTC has become the first state roadways in the country to provide 3D secure online booking and cancellation facilities.
The e-commerce portal has been developed by the state Information technology department. Commuters can book or cancel tickets on HRTC website called sugamHimachal.org.
While trying to check the availability of buses and seats I found out that currently this service includes only few places as source and destination. This includes Delhi, Dharamsala, Himachal Bhavan Delhi, Shimla and Manali.
Selecting source as Delhi and Destination as Shimla and wise versa works. All other places when you select them doesnt show any routes. So probably this is still under development I guess. But this is definitely a nice feature by state owned trasport corporation.
The online booking for Delhi to Shimla for a Delux bus type gives the following seating chart where you can select the seats according to your choice and availablity.