"As this is VSAN environment and having 6 hosts, we like to upgrade to 6.7 U3 on only one esxi host(lets say ESXi01) at this point of time "
As this is a vSAN cluster, you should be updating the whole cluster and not just one host.
"As per the above matrix,we can update the ESXi host directly to 6.7U3 without updating vcenter server 6.7 U3.Is this right?"
No, this is not right as you have selected the incorrect product (ESXi, not vSAN) - updating vCenter to 6.7 U3 before the hosts is required:
"How to upgrade vSAN cluster with best practices? - VirtuallySensei.com"
Sure, Hareesh's guide there is fine.
Thanks Bob for your response.Yes. we are going to upgrade the vCenter server first to 6.7 U3.
Post that,we are going to do ESXi upgrade to 6.7 U3.