DOnt Worry ,no need of admit card...In the press note link given in the website www.upsc.gov.in

they made it clear that one who didnt receive admit card can carry the venue information print out to the centre..

which you can get from the same site..(link-venue information for SCRA 2011 -- in that select regn no and type urs) 

carry ur photographs 4 each session of the exam..and something to prove ur identity..

     hope it was useful...

Download e-Admit Card for SCRA Examination 2012 from here http://upsc.nic.in/onlineadmitcard/main.aspx