Although most Hibiscus plants are best grown outside - they now appear to be fast becoming very popular as indoor plants which is possibly because they are such beautiful plants and although there are many varieties of Hibiscus - the most popularly sold Hibiscus for indoor growing is Hibiscus Sinensis - which is I think most probably the one that you have - which if grown indoors requires
reasonably high humidity and moderate heat
are best placed in a south or west facing window as they require at the very minimum - 2 hours of direct sun each day
need to be kept reasonably moist but not soggy and are best if allowed to dry out between waterings
and regular fertilizing with a low phosphorous fertilizer throughout the growing season which is between March to October
however they don't like temperatures that fluctuate and in particular cold drafts or low humidity - which if your indoor humidity is low due to air conditioning or similar - you may have to compensate for by lightly misting the plant on a daily basis.
I think I've covered everything but if not or you have any further queries - please feel free to ask