We are going to have a weekly yoga lesson for three weeks and then no lessons for two weeks and again class for three weeks etc.
Does this sentence make sense, please?
"We are going to try a new organisation which will consist in having a two-week break every three weeks".
Thanks a lot for your help.
"Organisation" doesn't work. Try "arrangement" or "system".
We say "consist of", not "in".
However, in your piece, I would use "... which will involve having ..."
Remember - correct capitalisation, punctuation and spacing make posts much easier to read.