For the "$/DisCo/Dev" folder of your VSO (Target End Point) in your Visual Studio Source Control Explorer, can you do right-click > Advanced (Properties) > Security. It will take you to the Permissions page. For the user in question "Pradeep Damodaran", please verify if he has proper permissions to do source control operations. The user being a part of the Administrators is not enough to outright access.
In the permissions, a Deny permission takes precedence over allow. So for example, suppose you are a member of Admin Users who have all the permissions. And also a member of Project Reader Users where explicitly some specific permission is denied. Then that deny permission would take precedence and your user wont be allowed to do that particular operation.
Verify that operation is being performed in the changeset which is giving you this error. And see if "Pradeep Damodaran" has permission to do that at the specified location.