Hello, hello!
I want to create a rule to create different subtask, but the subtasks need to be different, it depends on the market field.
So, if the task is added to a project, and the market field is DE, create a subtask that it’s going to be added to another project. If the market is FR…the same.
The problem is, when I select several options, the rule gets crazy and create the subtask several times. Does someone have a solution?
What’s your trigger? It shouldn’t “get crazy” 
Also make sure your rule only applies to tasks and not subtasks as well, might be a reason.
Welcome, @Virginia_Gutierrez_D,
If you’re still having trouble, please post screenshot(s) of your rule(s), masking any data as needed.
Thanks,
Larry
Hi @Virginia_Gutierrez_D , welcome to the forum 
If your market field is a multi-select field, it will create multiple subtasks. This is due to the limited options for the conditions for multi-select fields.
If tasks are added to the project using a form, this will only work if you have one rule for each condition, without any branching within a rule.
Otherwise, if you use a single-select for your market field, things will be much simpler using one rule with numerous branching conditions.