Is it possible to put delay between tasks or conditional loop

You can add an Agentless phase and put a Delay-task in it. Then your build will be delayed X minutes. Then you may continue your pipeline with an agent phase. Just make sure to configure Run this phase or set a dependency between the phases. This works in TFS and Azure Devops Server.

Put an in-line PowerShell task in place that runs Start-Sleep -Seconds 10 or however long you want to wait.

Or better yet, write your own script that polls your containers for availability.