Ranks can't be changed and no, the tasks ask for simple & direct mathematics concept unlike other 6kyus math-related katas

Well, reading it again, actually, doesn't it say twice the same? I think the first sentence is actually sufficient.

This is clearly stated in the first paragraph of the description.

Now I read the description, I am not exactly sure about whether it's clear enough. I think it puts pressure on the mapping only in one direction (from A to B), but I am not sure which part would clearly state that B also must map to A...

....and reverse: in the first example, R in the first word can be mapped only to T in the second word, and T in the second word can be mapped only to R in the first word.

In your example, C from the second word cannot be unambiguously mapped to any letter from the first word.

This is clearly stated in the first paragraph of the description.

Why is RAMBUNCTIOUSLY THERMODYNAMICS True but AB CC is not?

I assumed the Q meant each letter in a can only map to one other letter in b. E.g: A -> B or D -> Z but NOT: A -> B and Z -> B.

It is similar, however mine requires a loop, and also a bit of formatting.
And the output must be a list, not a single name.

This seems very close to being a duplicate of this kata. Yes you're asking to swap names in a list... but the concept seems too similar to me

I have fixed this, and implemented a random list generator as the last test.

Because the kata is back to draft.

Cant submit

carry on repeating the operation in the description until all the numbers are equal.

I feel as if this should be 6kyu due to the fact that you have to take into account runtime complexity.

Try to draw out the example - many people who tried this problem first came up with your solution. However, it might not be the optimal approach.