will a rearend from a 02 m6 car fit my 93 a4 car and everything work properly?

 

no really. will it.

 

If you swap the whole thing (including axles and brakes) and the rear end did not come from a traction control equipped car, then I think all will work. I'm pretty sure the ABS will work ok if the donor car was a non T/C car. I assume your car does not have T/C. I don't think it was even an option in 1993. You may want to wait for a second opinion about the swap.