Hi Suresh,
Thank you for reaching out to us. I see that you would like a production demo account so that you can replicate and simulate the functionalities and features in that environment. For this purpose we advise that you use test accounts, which should provide you with the same functionalities of production accounts with slight differences, such as not being able to run ads or set up billing.
Otherwise, you can test out Campaign Drafts and Experiments that you can use to make experimental versions of your campaigns to see how they would perform. Let me know if you have further questions.
Thank you,
Bryan, Google Ad