Spotting

Beautiful shot

First of all, the only buteo species present in that area are Oriental Honey Buzzard and White-eyed Buzzard, but personally I don't think it is either of these, but I could be wrong.
I think it might be a Changeable Hawk-Eagle but this brings up another problem as this bird is currently undergoing a split. The Genus was recently changed from Spizaetus to Nisaetus. Now it is proposed to split the Changeable Hawk Eagle from the Crested Hawk Eagle, which will now be the name for the dark form and the latest Clements 6.9 listing shows Changeable Hawk Eagle will now become Nisaetus limnaeetus, which currently does not appear on any reference web-sites.

Great capture!