COS এর পূর্ণরূপ কি | What is the full form of COS? Educational help June 26, 2022 COS এর পূর্ণরূপ কি?COS এর পূর্ণরূপ:-COS এর পূর্ণরুপ Charity Organisation Society.What is the full form of COS?the full form of COS:-The full form of COS is Charity Organization Society.