Hello Vinod,
I believe this article can give you a workaround if needed.
http://technet.microsoft.com/en-us/library/ff634208.aspx --"Backup of BMR of a Windows 2008 or Windows 2008 R2 server using only short or long term backup to tape is
not a supported senario. The reason for this restriction is for BMR protection, the Windows Server backup writes it's output directly to the DPM Servers replica volume via a network share. This is required because most likely there would not be enought space
on the local protected server to hold all the critical volumes data. As an alternate to this, the solution could be to schedule Windows Server backup to make a BMR backup to a network share on another DPM protected server, then schedule DPM to backup
that share directly to tape, thus accomplishing the same goal."
Thanks,
Shane