No idea and no way to tell. It's a busy field, with lots of top-notch, high rated courses and three best sellers so on the first view it would be hard but not impossible to be successful. Check out your competition and see if you want to dive in or not?
Also, check out your profile and you can't use computer-generated voiceover on Udemy. I understand why you would want to but it's against the policy and won't be approved for the marketplace. Your other options may be to have someone else read your script.
Well, you can at least get a range by using the Insights tool in your instructor dashboard:
You can see the median monthly revenue is $22 per month. As a new instructor, that's probably about what you should expect. On average one paid student will net you around $3-4, so that's around 5 students per month.
Although Blockchain is a hot topic, it's already saturated with high-quality, established courses that are hard to compete with. There are already 146 courses on this topic, and yours will be #147. You'll need to produce a course that offers more than what's already out there, and do good job of promoting it, in order to succeed in this category.