Disclaimer: I haven't completed FCC, nor have I gotten a job yet. Nonetheless, I'll offer my thoughts that are based on what I have seen, and what I've read from Quincy, himself.
Your question cannot be answered concretely, as it is really up to the person, and their drive to get a job. For example, some users complete only a portion of FCC, and get jobs. There are, however, variables at play here, such as: their area, their determination, etc.
Even then, there are sites like upwork, where you "bid" on jobs; there's a lot of them, ranging from basic HTML removal, to adding new HTML, to writing content for the employeer's website. With just FCC's HTML section, you can most likely succeed in such jobs. However, some of them require you to take a test based on your HTML skills.
But, I recommend to not worry about the job aspect right now. Focus on building your skillset, absorbing as much knowledge as you can. Don't stop at FCC. Check out some books, videos, etc. And take part in the chats, there are a lot of people that you could learn from.
There's no way to answer this, but I hope I offered you some insight, at least.
You can check out these as well:
I think Quincy can answer better than I can.