This lamp base is from Nepal. It is about 19 cm in height.
Generally, these are referred to as a butter lamp. Given the top portion is shallow it quite likely the top was used as a platform for an oil-and-wick lamp. However, the top portion shows burn marks from actual use.
The broad base with beaded rim, a fluted bottom portion with lotus petals, narrow waist, a lotus at the central portion and the top container sitting on an inverted lotus is very similar in design to the Surya lamp on this blog site.
I have no guess as to the age of this bronze, other than to note it looks like it was in use for a few decades.