Is it possible to find out whether iPhone has MLC or TLC NAND by serial or batch number? Is there any way to check whether the phone has MLC or TLC, just by serial number or batch number?

I will be buying iPhone 6, Space Grey, 64GB. From what I have read, 64GB version could be TLC or MLC.
You can't figure out the type of NAND from the serial number.
However, Apple is dropping TLC NAND, so it most likely has MLC NAND (however, I can't tell you for sure without you buying it.)