The 8GB memory you bought is a low voltage double data rate3 type dual rank error correcting dual in line memory modules with registeres (on the address lines?). They are compatible with your T610 and should  work without issue (assuming there are no previously unknown hardware faults). Which slots you place the RDIMMs into will depend on the BIOS Memory mode settings you specify. If i understand correctly, this in turn can have impact on the memory speed obtained.  I'd 1st set BIOS memory mode to "Advanced ECC" and place your RDIMS into the 4 slots closest to CPU1 leaving the furthest 2 slots empty. Then i'd run a memory benchmark to check the performance. You could also try changing BIOS memory mode to "Optimised" and place the RDIMM's into the 3 white slots with the 4th in the black slot furthest from the CPU (marked A4). Then run a memory benchmark and compare with the above configuration.  Either configuration should give you 32GB.  You don't mention what type, size or number of DIMMs you previously had installed within your system so it's impossible to say if they can be reused or how. But since you mention you are replacing them, i guess it's not relevant anyway. However, if your old memory was UDIMM type (unbuffered = no registers on data lines), it's safe to say you can't mix UDIMM's with RDIMM's. If you old memory were RDIMM's you may be able to reuse them (but if they are not low voltage type, you will not get the low voltage benifit from your new memory as it will work at thehigher voltage and thus consume more power than would otherwise be the case).   Good luck.
I have server Dell T610 with one CPU E5506. I want take out all memory from the server and install new 4 memory rank 8Gb 2Rx4 DDR3 RDIMM 1333MHz LV (Snpp9rn2c/8g). Will be ok? I got 32GB? Will with memory work correctly with CPU E5506?
Dell T610 Memory Upgrade