Yes you are eligible to appear in all group of December 2012 attempt.
Admission to the CS Course is open throughout the year. Examinations are held twice a year in June & December.
Cut off dates for admission to CS course:
For Foundation Programme :31st March for appearing in December Examination in the same year and 30th September for June Examination next year For Executive Programme:
28th February for December Exams in the same year and 31st August for June Exam next year.