I created new VM and later add the 2 existing HDD but while it boots for few second in windows but finally throws error in booting up the windows 2016 give us an option to continue, troubleshoot or power-off, so I power-off the VM & removed it from inventory.
I downloaded the original vmx file, changed the memory in the multiple of 4 MB, i.e: 64 GB & uploaded it again to datastore.
Boooted the system, now memory reflecting appropriately.