Upgrading old RCA tablet from Android 4 to Android 5?

[Sir Dude]

tl;dr: Can I upgrade from Android version 4 (Kitkat) to Version 5, or any other later version?

It's an old RCA tablet from Walmart.
Model number: RCT6203W46
Android Version: 4.4.2

Kernal Version: 3.4.67

Build Number: (model #)-(android version)V51-V1.9.50

 

Context:
I wanna draw digital art, but I don't wanna buy a whole new piece of kit just so I can lose interest after a month and not touch it again for a year. I've got this old tablet from high school lying around and I looked into turning it into a drawing tablet. Turns out, you can just download an app for that. I found one called VirtualTablet and it gives you 3 options for connecting, WiFi, Bluetooth, and Tethered. Of course, the wireless options are laggy, so I chose Tethered. And... it's only supported on Android 5 or later. So now I've spent the last 5 hours trying to flash, update, and research this tablet. I understand upgrading Android OS's isn't exactly a safe thing to do, and you've gotta make sure it'll even run on the device, but is it even possible? I can't seem to find a straight answer and of course I've got this seemingly unknown device that's hard to find documentation for.

[Kilrah]

Basically the only way it'd be possible is if someone made a custom ROM for that particular device. You can search sites like xda-developers to try and see if there are some.