Is it still eligible for ADN US graduate to get a green card ?

The problem would be more that if retrogression is still insitu and you do not have OPT then there is no way to stay unless continuing study as retrogression means no visas so nothing to adjust your current status

You are eligible for the green card, but the issue is that there are no visas available for you to adjust to and we do not expect any to be available next year. For you to be able to remain in the US and work, it requires that you have the OPT, and the I-485 petition can be accepted, that is where you are going to have issues with.

Otherwise, you have 60 days from the last day of class to remain in the US if you do not continue on with your schooling and maintain the F-1 status.