You may choose any organisation you like – business or non-business (not-for-profit), local or overseas. But it MUST be a real organisation. If you choose a large organisation, it may be sensible to focus on one aspect or division of its operations. Often, small organisations may be ideal as your ‘client’ for this assignment.
Your key aim should be to show what public relations can do for the organisation and to make some practical recommendations for action. Imagine you are a PR consultant and this document is your first written submission for a new client (give your consultancy a name).
Obviously you will need to gather background information about the organisation. Ideally talk to people who work there in addition to examining as much other material as you can, e.g. website, brochures, sales literature, annual reports, advertisements, relevant newspaper and magazine articles, etc. If possible visit the organisation to interview key employees/stakeholders. Choosing a firm you have worked for is a good idea.