Leaf Beetle

Yes, indeed, Zygogramma is the other genus of these Calligraphic beetle. And yours is a nasty example of intruders. Nasty for IDing, since you first do not think of a species/genus native many thousend of miles away. I was suspicious about htese ones found in India, but did not have the time to check also for intruders. Congrats for the ID of this one! Seems to be the correct one.

Chrysomelidae, Chrysomelinae, probably Chrysomelini. Nice one! I did not know that you have such kind of "Calligraphic Beetle" in India. Calligrapha is a species from the Americas, so you might have similar one. Please, check the leaf beetles in India. Cave: I might be completely wrong due to being mis-lead by similarity of the American beetles...