A formal responsibility assigned to a person, often related to their job or position.

आधिकारिक कार्य

English Usage: His official duty required him to attend the meeting on behalf of the mayor.

Hindi Usage: उसकी आधिकारिक कार्य उसे मेयर की ओर से बैठक में उपस्थित होने की आवश्यकता थी।