It's a lily. :)

Lilium orientale variety, might be 'Yellow Pixie' but there are hundreds of varieties - they're bulbs, so you can increase them by growing on the little, offset bulbs the parent bulbs produce - each bulblet will take a few years to get big enough to flower - further information in the link below

http://www.mikesbackyardgarden.org/lilyprop.html

I was thinking an Asiatic Lily hybrid, myself, though the same methods apply. If it is an Asiatic, it will also produce tiny bulbs near the top of the stem, which can be grown on the same way.
Both kinds may have biorhythm problems in the truly tropical parts of India, since they need a little chilling in winter.