That figure is an estimate of the production budget only. In order to know the estimated gross profit, we'd have to have some sense of the promotional and distribution costs. For a tentpole like Tenet, those are usually pegged at pretty near the production budget. So, call it $400 million.

In other words, its pretty unlikely the theatrical run yielded a profit.

A general rule of thumb is a movie needs to make back double its budget to recoup after-filming costs, like advertising, ect to start turning a profit. A $363 million return on a $200 million flick is not a good return.

Warner Bros does not get all of the $363 million at the box office, the theatres takes their cut. For domestic gross it's said to be roughly 50/50 during a box office run, with the distributor (in this case WB) getting the most during the first week, and then the theatres get the most, for Foreign gross it's much less, with China only giving 20% of the box office to foreign distributors.

Also the $200 million production budget does not include promotion/advertising.

So it's very unlikely that Tenet made a profit at the box office, however there's streaming deals, physical media etc which can earn a pretty penny, particularly if something becomes a cult classic. Blade Runner and Starship Troopers were box office failures having has made lots of money afterwards.

^ Something that can only be said because the only competition is the latest set of horrific Star Wars movies.