Kindly help!

Maybe. What are the symptoms? And which sort of box is it anyway?

It is 01M927733LC Automatic Gear Box Control Unit,

The symptoms simply are an overall performance degradation, car start to go on the 3rd gear, & wont switch between gears on normal drive; in other words it wont change between gears in the ride (sticked to the 3rd gear), this is causing troubles when you need the initiation power (start up).

Another major symptom is that the front control panel gear lights are continuously blinking.

Can you still get first and second with the manual shift?

Yes sure, actually I'm totally depending on shifting between 1,2,& 3,

Gear hardware is totally fine, no problems reported about the gear box.

Ok, what sort of mileage are you on? ZF transmissions recommend replacing the gear oil in their autos at 50_000 miles (80_000km), and I know several people who have cured intractible problems with the electronics in Citroen C5 autos by chaning the gear oil.

Actually gear box oil was changed as a first trial for recovery, but without any use.

My Octavia has done 60,000 Km (40,000 Miles) now.

You've exceeded my knowledge now. All I can suggest is taking the car to an automatic transmission specialist rather than a car dealer.

Will do.

Thanks for your help!