Geoff, thank you for your suggestion.
John, thank you for your view. In fact I cannot say for sure. Although I know female of Blue Rock Thrush can range from dark brown to greyish blue above, but the blue colour of the bird in question got me to think that it looks like a male. And the blue apperance made me think it was a Pandoo. With my very limited exposure, most if not all of the female photos I have seen before were brown.