I have 4 groups of questions, randomly I assign just one group for each participant.

I am using a hidden question with 4 options, so I can set a quota for each option.
I go for 200 completes, 50 completes for each option.

But I don't want people to terminate if the one option is full with the 50 comples and another option not.
Is there a way to check the quota status in the survey and to assign a different option when the option is already full?

I don't see a way to do this without manually adapting the quota according to the "fill status". Unfortunately the quota in LS are either full or not and when full you get screened out.

And you can't access answers of others either in a questionnaire.

However, there is a plugin from Denis Chenu, that allows to check statistics at the current state. So maybe it is possible to use this to read out the current count for each quota. But I have never tried the plugin. You might be able to read the database via Ajax or something and then adapt the quota. But this will definitely require some custom coding.

Thanks again for looking into this!

Yes good one, I think I will go indeed for an ajax call, external php page to check the mysql database directly.