GUI design – What is the best place for an information icon on a form?

Make the labels as clear as possible that no additional information is required. In some cases this is not possible. In this case, such an information symbol (probably a tooltip will open) may be helpful.

The overall layout affects where the icon should be placed. The info symbol near the label indicates the user context.
Option 2 looks more visually appealing at first glance, but at second glance you can see that the symbol is sometimes unrelated, for example: at the sex.
Option 3 may have the same problem and you are losing space for the input fields, which may be a problem on mobile screens.

So I would suggest going with option 1.

Another thought: I wonder what the information in your tooltips would look like, because the labels in your example are very clear. If you think about using the tool tips to give instructions for filling in the field (minimum number of letters, password rules, etc.), the tooltip is the wrong pattern. In this case you should enter the information below the field.