Yes, you can apply Company Secretary Course after completing B.Com; you will be exempted for the foundation level. You can get direct entry in the Intermediate level course.

Fees of the CS course:
Foundation Program
Duration: 8 months.
Course Fee: Rs.3,600/-
Examination Fee: Rs. 875/-

Executive Program
Course Fee:
Rs. 6,500/- for Foundation Program passed students.
Rs. 7,000/- for Commerce Graduates
Rs. 7,750 for Non-commerce Graduates
Examination Fee:
Rs. 900/- per module

Professional Program
Course Fee: Rs. 7,500/-
Examination Fee: Rs.750/- per module