Hello @pankaj kumar ,
Thanks for reaching out to Microsoft QnA. Happy to answer your question.
No, you cannot set the private address of the VM to be same as that of the public address. Both private and public addresses have separate address ranges and have a different purpose. If the developer wants to access the web server from the Internet, he will require the public IP address.
On the other hand, the private address of the VM is only private to the virtual network that the VM is associated to, and cannot be accessed from Internet. Only the resources that are part of the same virtual network can access the web browser VM using the private IP address. Whereas, anybody outside the virtual network will not be able to access the VM using private IP address, but has to access the VM using it's public IP address.
Hope this explains the usage of public and private IP addresses.
Please don't forget to and if you think the information provided was useful so that it can help others in the community looking for help on similar issues.