You need to add few permission roles, follow steps below,
The steps for configuring SharePoint Server role permissions are as
On the RMS server, navigate to C:\Inetpub\wwwroot_wmcs\Certification.
Right-click the ServerCertification.asmx file and choose Properties,
and then click the Security tab.
Click Edit and then Add. Click Object
Types, select Computers, and then click OK.
Enter the name of all
SharePoint web roles servers into the box and then click OK.
Add. Technorati Tags: AD RMS,Information Rights Management,SharePoint
2010 Select Object Types of Groups, and then click OK.
RMSServer\AD RMS Service Group (where RMSServer is the name of your
RMSServer), and then click OK. Review the security settings, which
should be similar to what is shown in Figure 5.
Figure 1. Modifying the security on the ServerCertification.asmx file
on the RMS server.
Click OK to close the security dialog box.
If that doesn't solve your solution then,
To use IRM in Office SharePoint Server 2007, you must install the
Microsoft Windows Rights Management Services Client, version 1, on
every front-end Web server in your server farm. In addition,
Microsoft Windows Rights Management Services (RMS) for Windows Server
2003, service pack 1.0 or later, must be available on your network.
To install the Windows Rights Management Services Client, and for
additional information about Microsoft Windows Rights Management
Services, visit the Windows Rights Management Services Technology
Center (http://go.microsoft.com/fwlink/?LinkId=73121). For a
description of the steps needed to configure Microsoft Windows Rights
Management Services to allow Office SharePoint Server 2007 to create
rights-managed content, see Deployment for Office SharePoint Server
2007. For more information, please refer to: Plan Information Rights Management (http://technet.microsoft.com/en-us/library/cc261728.aspx)
For more information