In later versions of RealFlight you can in fact filter for drones in the Quick Select dialog. But in 7.5 you can only filter for airplanes and helis, with drones being lumped into the latter category.
RF7.5 contains the following drone-type models:
- Explorer 580
- Gaui 330X-S Quad Flyer
- H4 Quadcopter 520
- Heli-Max 1SQ
- Heli-Max Voltage 500 3D
- Hexacopter 780
- Hexacopter 780 (GPS Modes)
- Octocopter 1000
- Quadcopter
- Quadcopter (Classic)
- Quadcopter X
- Quadcopter X (Classic)
- Tricopter 900
- Tricopter 900 (Manual Modes)
- X8 Quadcopter 1260
Two additional models are available as unlockable challenge rewards:
- Dead Cat Quadcopter 580
- Eldritch Copter
You may find it useful to know that the following additional models are available in RealFlight 9.5.
- Heli-Max FORM500
- Hubsan X4 Pro
- Hubsan X4 Pro (Prop Guards)
- Rise RXS255
- Scorpion Sky Strider 280 (5 Degree Arm Angle)
- Scorpion Sky Strider 280 (10 Degree Arm Angle)
- Tempest 250
- Tempest 250 (Angled Camera)
- Tempest 280
- Tiny Terror 150
- xCraft X PlusOne
- Xiro Xplorer
- Xiro Xplorer G
I should note that these cover a wide range of different drone designs and functionality. Sometimes people load up a camera platform like the Quadcopter X or Octocopter and complain it doesn't fly like their race drone, or vice versa. So it's important to pay attention to the intended purpose and design of each model. They are good simulations of the technology they were emulating at the time, but that particular branch of the hobby underwent a tremendously rapid evolution, with the technology and capabilities changing and improving seemingly monthly. Later on we designed a more modern race drone type of flight controller component, and users can make use of it anywhere they like, but the only stock model that uses it is the Rise RXS255.
I should also note that RF9.5 has an on-screen Flight Modes gadget that is incredibly helpful when flying drones. It tells you which modes the currently loaded model supports (e.g., Loiter, Acro, Return to Launch), which one is currently selected, and if you mouse over the '?' icon it provides additional information about what each mode does. Without that, you have to read the vehicle descriptions to know what modes they support and keep track of everything on your own.
I hope that helps!