Thanks LucD for update..I found some way to register multiple vms as below..This helped me a lot..
New-VM -Name test1 -VMHost 10.xx.xx.xx -VMFilePath “[SAN_datastore] test1/test1.vmx“ >> D:\\VM-Reg-Out.txt
New-VM -Name test2 -VMHost 10.xx.xx.xx -VMFilePath “[SAN_datastore] test2/test2.vmx“ >> D:\\VM-Reg-Out.txt
kept in .ps1 file and executed..It worked.