Here are bus timings from Coimbatore to Bangalore by private buses:
Orange Tours Travels
Volvo A/C -Multi Axle Semi sleeper (2+2)
Dep 23:30
Arr 05:30
Golden Pearl Travels
Non A/C Sleeper (2+1)
Dep 23:55
Arr 05:45
INR 1100
Sam Tourist
A/C Sleeper (2+1)
Dep 23:45
Arr 06:00
Greenline Kerala
A/C Sleeper (2+1)
Dep 23:45
Arr 06:00
Sam Tourist
Volvo A/C Seater (2+2)
Dep 23:30
Arr 05:30
Kallada Travels Suresh Kallada
Scania A/C Multi Axle Seater (2+2)
Dep 23:55
Arr 06:00
SPS Travels India
A/C Sleeper (2+1)
Dep 22:30
Arr 06:00