Hi anil kumar
You can enable VM insight through Azure portal or method of your choice
https://learn.microsoft.com/en-us/azure/azure-monitor/vm/vminsights-enable-portal
Once done you can use following KQL Query to get the details
InsightsMetrics
| where Origin == "vm.azm.ms"
and Namespace == "LogicalDisk"
and Name == "FreeSpacePercentage"
| extend Disk = tostring(todynamic(Tags)["vm.azm.ms/mountId"])
| summarize Disk_Used_Space = 100 - avg(Val) by Computer, Disk, _ResourceId
| project Computer, Disk, Disk_Used_Space