Which ESXi version are you planning to install on the new server? If you can share the exact version I can share the list of server supported for the same. E.g. below link have Dell EMC PowerEdge Servers Compatibility Matrix for ESXi 7.X

https://www.dell.com/support/manuals/en-us/vmware-esxi-7.x/vmware_7.0.x_vsphere_compmatrix_pub/dell-emc-poweredge-servers%E2%80%94compatibility-matrix?guid=guid-542042f7-599c-4721-8d3d-77a33f6e07d3&lang=en-us 

You can also use below VMware link to check compatibility. 

https://www.vmware.com/resources/compatibility/search.php 

thank you for the reply,

these are the VM configurations now running on the R710.As I check ESXI 6.0 U3 is the latest possible version that i can go.
but with the very old hardware maybe it can be a risk and its discontinued server.
furthermore, even it works fine with normal operation with the workload sometimes VMs get little bit laggy.
Therefore I'm planning to upgrade the server.
I need to find the best option for my situation and work fine next few years with updates.

You can refer below link for a list of supported PowerEdge server for ESXi 6.0

https://www.dell.com/support/manuals/en-us/vmware-esxi-6.x/esxi6.xvsphere_compmatrix_pub/dell-emc--poweredge-systems%E2%80%94compatibility-matrix?guid=guid-3ab286dd-e15b-494a-9c00-5c6cbd15363b&lang=en-us