No, this is not possible. It is like trying to put the engine of a truck into a small box for use as a pump in your fish tank.
Theoretically, small VB 2010 code parts can be pasted into a VB6 project with more or less additional work afterwards, but practically, you either have to learn VB6 or upgrade the VB6 projects to VB.Net or rewrite them in VB.Net.
Armin