The obvious difference between two species being the V. trifolia has leaflets 3-foliate and glossy - while the V. negundo has 3-5 (rarely 3) and dull.
Nochi, the Tamil name, commonly refers to this plant, the five-lobed Vitex negundo. It is the 'prefered nochi' in traditional medicine probably due to the stronger scent its leaves have, which they readily release even when brushed against.
But the Vitex trifolia is a more common house-plant in Singapore as it has a neater appearance, I think.