Read about Karnataka State Road Transport Corporation-www.ksrtc.in here.
The online booking / reservation system of the KSRTC (Kerala State Road Transport Corporation) is inaugurated by Chief Minister V.S. Achuthanandan few months back.
There are around 17 Kerala RTC bus services are there from Bangalore to Kozhikode. The booking can be done on www.keralartc.com using credit or debit cards. The online booking charge is Rs 20.
You can book the tickets online at :http://220.127.116.11:8080/KsrtcOnlineR/ You can check the ksrtc bus availability on different routes here :http://18.104.22.168:8080/KsrtcOnlineR/busAvilable.do?action=busAvlGnrl