A notice is a type of social communication used to notify or present information to a specific set of people.
The correct word is communication. "Conveyance" relates to transport, and "conversation" is informal/two-way. A notice is a formal, one-way written communication directed at a specific audience — so "communication" fits perfectly. Note: the source passages provided do not directly address notice writing, so this answer is based on standard CBSE English grammar knowledge.