Typically, a PUT request URI looks like below accepting the actual payload in HTTP body.
In Service Bus12c, We cannot mix URI parameters with representation of the resource, when we want to define a resource in this way.
If we run Proxy Service with this setup, we will get an error as shown below.
Instead, you can use the expression as shown below.
You can access this using the following expression from your message flow.
$inbound/ctx:transport/ctx:request/tp:user-metadata[@name=”empid”]/@value
If you log $body and above expression, you would see the log messages as shown below.
As explained in this link, you may have to populate these URI parameters in outbound variable.
Siva's Blog 
How did you do it?
Hi Siva,
My rest business service expects a template parameter. How can I set the value of that template parameter in pipeline before routing to the business service?
How did you do it?
Thanks for the blog.. Do you how we can achieve the same in SOA 12c using REST Adapter ? URI parameter is not part of the payload.
REST adapter would be the same for SOA too. What’s the issue you are seeing here