The Blue Tiger Butterfly is native to South and Southeast Asia.
There are several very similar-looking butterflies, including the Dark Blue Tiger (Tirumala septentrionis) also of South and Southeast Asia, the Scarce Blue Tiger (Tirumala gautama) of India, the Blue Tiger/Blue Wanderer (Tirumala hamata) of Australia, the Blue Glassy Tiger (Ideopsis vulgaris) of Southeast Asia, the Glassy Tiger (Parantica aglea), the Dark Glassy Tiger (Parantica agleoides), the Chocolate Tiger (Parantica melaneus) and others. As well as individuals varying and several subspecies, there are also mimics/look-alikes using inedible Danaids as protective camouflage.
The male has a small brown flap (pheromone pouch) on the hind wing (shown above
left) and the female (above centre/right) has continued blue colour instead of the flap.
The black and white body spots warn potential predators that these butterflies whose caterpillars have eaten milkweed are distasteful and poisonous.
This one could be a Scarce Blue Tiger -- see link below.