Hello,
I need to have different questions based on a user group selection.

Example: if at registration user select couple it will have 2 questions for height_male, height_female but if select the group man only height_male will be shown and for woman the height_female will be shown

How I can achieve this?

thanks

You can easily achieve this through RSForm Pro Conditional fields. In your Administration page go to Components >> RSForm! PRO >> Manage Forms and create or edit your Registration Form and add a radio group with the values Male, Female, Couple one per row. After all the fields are in place even the "Man height" or "Female height" that will be displayed conditional, go to Properties tab, choose Conditional Fields from list and add a New Condition.
For "Man height" to be displayed choose Show >> block(label+field) >> Male height if any of the following match: and click the + icon twice. On the first row choose Radio is Male and on the second one Radio is Couple. Where the Male and Couple are options from the radio group you added before. All you have to do next is to add a new condition for "Female height" in the same way.

More about Conditional Fields here: www.rsjoomla.com/support/documentation/v...ditional-fields.html