You'll show this as a coversion from personal use to residential rental real estate in 2016. As you work through the Rental & Royalty Income (SCH E) section of the program, when you get to the expenses part, there is an entry box specifically labeled "management fees" and you'll enter it there.
Also, your reference to "realtor" is not accurate for this specific purpose. If you are paying them to manage your rental property, then the correct reference to them would be "property manager". It's very common for a realtor to be the property manager for rental property. But when you refer to them as "your realtor" it can call into question if you are paying management fees, or something else.
