Hi. It depends what you mean by Online Reputation Management, definition is key.
I have been doing SEO and ORM for years, every client and requirements are different.
For example, If all you need is to clear the 1st and 2nd search result pages on Google for specific terms - that's one thing. But, if you need someone to manage reviews of your GMB, Facebook, Yelp... that's another and is more time consuming and complex.