Dell Precision T5810 adding 32g memory slot loading

Have 32g 4-8g installed in machine Hynix brand. All memory have same specs. I have found posts that say yes not a problem and no. Bios updated Currently Xeon E5 2660V3 10 core GTX 1080ti.  Can I add the below 32 gigs 2x16g Samsung memory and if so which memory slots have 4 more open? Does the 2-16g Samsung memory have to install in slot 0? Eventual goal is 64 gigs total All memory ECC

HMA41GR7AFR8N-TF Hynix

SAMSUNG Model  M393A2G40DB0-CPB3Q

Details Capacity 16GB

Type 288-Pin DDR4 SDRAM

Speed DDR4 2133 (PC4 17000)

Cas Latency 15

Voltage 1.2V

ECC Yes

Buffered/Registered Registered

Rank 2Rx4

Heat Spreader No