Novetus needs a Windows OS with a x86 processor. This is a limitation of the older roblox clients.
Unless you want to mess with ExaGear with Wine on Linux or Win86Emu on Windows RT, Its not possible.
Even if you get Novetus working with ExaGear or Win86Emu Please use it to only host servers using the 2009E client in No3D mode. The RPI has awful 3D graphics and almost no RAM and ExaGear and Win86Emu will slow down the system ALOT.