There's a show called "What Would You Do?" and I was wondering if you can put a comma after the interrogation mark.
For example:
What Would You Do?, the popular hidden camera show, was canceled by NBC.
This is a question of style not grammar. Different style guides recommend different approaches. The question should not be "Is this possible?", but "Is this necessary?"
It looks a little strange, but in this particular case, where the question mark is part of the title, it is probably necessary. You can make it look less strange by emphasising the title. You should put titles in an italic font, and you could use quotation marks
The show Who do you think you are?, which was broadcast on the BBC, features celebrities researching their family history.
In many cases it would be possible to rephrase to avoid the awkward punctuation.
NBC cancelled its popular hidden camera show What Would You Do?.