@Gokulraj Mani, Thanks for posting in Q&A. If you do not see the MDM policy to configure GPO enrollment, you’ll most likely don’t have the ADMX Windows 10 1709 or later. And the device is with an old version.
Note: Non-Microsoft link, just for the reference.
You can download and install the later version admx adml to get the policy setting.
https://www.microsoft.com/en-us/download/details.aspx?id=104677
As another recommend option, please upgrade the windows device to latest version.
Hope the above information can help.
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