Yes, I think so too with this antennae segments ratio, though this species is normally located in Sri Lanka... The Indian species are R. gahani, R. fontanieri and R. subopacus but all features third antennal joint shorter.
There is another possibility: in Andaman island (close to Nicobar) another species is located: R. andamanicus (Gahan, 1894) which I don't know the type. So, as your specimen shows some differences with taprobanicus on the pronotal shape (anterior angles spiny) and antennae (third antennal joint a little bit longer), I think that it could belong to this species.