As long as its valid JSON, the data structure is your choice. You have full control over the incoming data, so whether it is one record or 1000, that shouldn't create a problem.

ahmedA - Thanks for your response.
JSON link here is the one generated through JSON event.
If bulk data is pushed , will the payload still be same?

The payload will be whatever data you push. I'm not sure, but it appears your problem isn't pushing data, but processing it.

My payload is shown as below:
Customer has a below ask:
 
The provided Payload is for handling single case record only not flexible for Bulk records handling. For handling bulk type records the payload should be in array format then it will be flexible for Single record and bulk records also.

Like I said earlier, the payload is whatever data you send it and your problem isn't with sending data, but instead processing it. I'm sorry, but there's nothing I can add here.
If you'd like to get a custom solution developed for your exact use case, you can drop me a PM or book sometime on my website.
Thanks.