I have been working for relatives for more than a month, and my relatives refused to give me this month's salary on the grounds that I can't work. Is it reasonable?

First, you should make it clear before you go, such as how long you will work, how to work and how much you earn a month. Dude, be clear. If these things are made clear in advance, there will be a lot of wrangling later.

Second, I don't think you can work well. Why didn't you say so earlier? Do you have to wait until you finish the work? Obviously, you don't want to pay your job, but you can't refuse to pay you. This is absolutely unreasonable.

Third, don't let it go just because he is a relative. You must ask him for your salary and safeguard your legitimate rights and interests. You've worked for him for a month, and you deserve to be paid.