Absent any other info, I'd pick tutoring over an online course. But tutoring is like taking piano lessons--they only tell you what to practice and how to practice it, and when you come back, they're going to tell you what you've been doing wrong. The vast majority of the practice is done on your own, which means your results are largely a product of how much time you set aside for it.
Lots of people prep with full-time jobs, so don't think that you can't. But just about everything else gets sacrificed to get those last 4-5 hours of awake time in every day.