While men have sued Hooters for sex discrimination, there has been no definitive court ruling on whether Hooters may continue to hire only young women to be servers at their restaurants. Thus, as a matter of legal rights the man is not right to sue.
Suits against Hooters proceed on the idea that Hooters servers are mainly in the business of serving food. If this is the case, then there is no reason to discriminate against men since men can serve food just as well as women can. Hooters, by contrast, has argued that being female and having a certain body type are bona fide occupational qualifications. The restaurant argues that selling female sex appeal is an integral part of their business model. Therefore, they should be allowed to discriminate against men in their hiring practices.
When cases like these have been brought, they have not gone to trial. Hooters has hired men to work in less visible positions, but it has not gone away from its practice of hiring only young women with certain body types to work as servers.
If you are asking about whether a man would be morally right in suing Hooters, it is solely a matter of opinion. I would argue that it should be clear that Hooters needs to have female servers and that the man should not sue. As a matter of law, there has been no finding that Hooters must hire men as servers.