Forums of the Megaverse®

How about ideas for Primitives races?

A number of them have already appeared in the permanently tagged Fan Races thread.

Rifts Thundercloud has a number of tables you can use, in combination with those from Rifts PhaseWorld and Heroes Unlimited Aliens Unlimited to create your own primitive peoples; just put a cap on the access to technology they have(with a definition of what defines 'primitive'...some advanced tech species might consider Victorian-era Earth, with its steam power and telegraphs, to be 'primitive', while our own age might define it as 'barely risen above using a fire').
Robbing the Palladium Fantasy Roleplaying Game and the Lands of the Damned minion creation chart can also yield you endless possibilities for primitive peoples.
Heck, D-bees of North America also has a number of primitives, and you can also use PFRPG and Dinosaur Swamp's tribal OCCs for fleshing out the skill sets of primitive peoples.

Go wild with those resources, Gaby. Roll yourself up worlds of primitives.

Sadly the answer your going to get to questions like this is to go check the 50+ page fan race thread and see if you can find something that might work.
*shrugs*
I know, I know. A lot of people have already done races and submitted them there.

I will say this...
...you first need to decide what you mean by "primitive races" and go from there.