Your coin has a laureate head, so it is probably not copying Constantine I. He is always depicted with a helmet except for one instance. The only VLPP issue that has Constantine with only a laureate head is a rare issue from Arles; a city which also struck the same bust type for the other rulers. Having said that though, having the wrong bust type does not necessarily mean that the engraver was not copying Constantine I, since these unofficial coins often stray quite a bit from official products.
Unofficial Arles VLPP's are not frequently encountered either. In fact, the overwhelming majority of these are Siscia imitations. It is most likely a Siscia copy and it looks like there might be a retrograde S in the exergue. Plus Siscia had several issues only for Licinius I with laureate head.
the first coin below is a Constantine from Arles and second is a Licinius from Siscia