Hi Jay,

Radio buttons type is not supported in lookup rule for new designer, but you can do it with in Forms 11 Update 3, where the new designer supports the Javascript feature, and use a combination of onLookupDone(handler, options) and setFieldValues(id,value) functions, you can refer to https://doc.laserfiche.com/laserfiche.documentation/en-us/Default.htm#../Subsystems/ProcessAutomation/Content/Forms-Current/Javascript-and-CSS/TheLFFormObject.htm for all functions that can be utilized.

Here is an example how I make it work:

LFForm.onLookupDone(function () { 
  //change to any condition you like
  if(LFForm.getFieldValues({fieldId:4})==1){
  LFForm.setFieldValues({fieldId:2}, {value: "Choice 1"});}
  
}, {lookupRuleId: 1});

The fieldId: 4 is a Single Line to be filled by lookup rule, fieldId:2 is a Radio Button field.

Once the lookup rule is done, it first check the value from fieldId: 4, and when it meets some conditions, set the proper option to the radio button.