Urgent help required

I passed CS executive both modules in June 2013. Registered myself for CS professional on Aug 26.2013(ie before aug 31.2013).

I know as per rule I am eligible to appear in all 4 modules in june 2014. 

Is it possible to appear in atleast 2 modules in dec 2013 itself?

Because my friend says that you can apply for exam enrolment for dec 2013 for 2 modules and admit card will come.

Help me.