Oops checked the bengali spelling: the name is pure r- not wr- or br-, so not clear why he writes it with a wr.
The root is then from Rdh, which means the same as (and may be alternate form of vRdh), and is also very old. Rddhi, however, has more of the connotation of prosperity rather than growth, and so is more suited for name use than vRddhi, even though they mean the same.
In some Bengali pronounications, the initial vowel R is more like Rhi than Ri. As I already mentioned, elsewhere in India today it may be Ru instead. But, Wr is definitely creative, or some local convention.