Converting a 5 family to a 6 family

[Ryan Delauz]

I am currently purchasing my first multi family property. It consists of a 4 family building and a seperate 2 family building. The 2 family building currently has an illegal 6th unit. All it needs is to finish the kitchen. I was told it used to be a 6th family but was changed to a 5 family. To change it to a 6 family would I need to get a variance from the town or could a permit suffice? Still learning on what to do with all these legal issues. Do I get a hold of the town's building department and ask them? Do I have to legally be the owner first before calling?