I can not confirm which bulbul this bird belong. I saw this bird was together with a few birds of White-bellied Yuhina which is probably twice or three times as big. Feet are black and so the beak which much different from Ochraceous Bulbul and with this clue that lead me to identify as Puff-backed Bulbul though much doubtful that the back color of the bird is not that puff but more like olive.
Anyone could identify for me for actual name of this bird. Thank you.