@Brenda Rojas The OS type is fetched from VMware APIs. It could be based on the VMware VM configuration template.
Please run the below commands to get the OS Type from VMware API.
Run the below commands on VMware PowerCLI installed machine.
PS > Connect-VIServer -Server <> -User <> -Password <>
PS > $vm = Get-VM -Name <>
PS > $vm.ExtensionData.Summary.Config.GuestFullName