A worldwide community photographing and learning about wildlife
Papilio polytes
The Common Mormon (Papilio polytes) is a common species of swallowtail butterfly widely distributed across Asia. This butterfly is known for the mimicry displayed by the numerous forms of its females which mimic inedible Red-bodied Swallowtails, such as the Common Rose and the Crimson Rose. The female of the Common Mormon is polymorphic. In South Asia, it has three forms or morphs. These are as follows: Form cyrus: This form is similar to the male, differing in that it always has strongly marked red crescents. It is the least common of the three forms. It is normally abundant where the Common Rose or Crimson Rose do not occur, such as in Himachal Pradesh around Shimla; although a few specimens of form romulus have also been caught alongside. Form stichius: This female form of the Common Mormon mimics the Common Rose very closely. This is the commonest form wherever the Common Rose flies. Form romulus: This female form mimics the Crimson Rose and is common over its range. It is not such a close mimic as the previous form being duller than its model, the Crimson Rose. It is easy to differentiate the mimics from models by the colour of their body—the models are red-bodied and the mimics are black-bodied. SOURCE: Wikipedia
I think this is probably a female, Form Romulus.