There are many avenues for an establishment like a restaurant to conduct social media marketing. Sites specific to their industry domain like Yelp and Zomato are some obvious choices while Facebook too is an important option to explore in order to reach out to the sheer number of people that use the website/app.
On the other hand, Instagram might also prove to be very helpful given that it allows for the focus to be on photos of the restaurant and the food served there, while still keeping the post trending with the right captions and hashtags. Whichever social media site you choose, there will be a need to curate the content being posted in order to get the maximum outreach or number of responses to the post.
Such an important task is best executed by professional third-party companies that focus on social media optimisation/marketing, content creation and search engine optimisation.
SEO Services India is one such company that offers all these services and more including Facebook marketing and online reputation management. Their techniques have put companies in the top ten ranking of Google search results and you can do the same as well.