Selected 2

import 'package:flutter/material.dart';
import 'package:gap/gap.dart';

String selectedGender = 'Male';
final listGender = ['Male', 'Female'];

Column(
  crossAxisAlignment: CrossAxisAlignment.start,
  children: [
    const Padding(
      padding: EdgeInsets.symmetric(horizontal: 16),
      child: Text(
        'Gender:',
        style: TextStyle(
          fontWeight: FontWeight.bold,
          fontSize: 14,
        ),
      ),
    ),
    const Gap(10),
    ...listGender.map((e) {
      return RadioListTile(
        value: e,
        groupValue: selectedGender,
        onChanged: (value) {
          if (value == null) return;
          selectedGender = value;
          setState(() {});
        },
        title: Text(
          e,
          style: const TextStyle(
            fontWeight: FontWeight.w400,
            fontSize: 14,
          ),
        ),
        controlAffinity: ListTileControlAffinity.trailing,
        contentPadding: const EdgeInsets.only(left: 16, right: 10),
        dense: true,
        visualDensity: const VisualDensity(
          horizontal: VisualDensity.minimumDensity,
          vertical: VisualDensity.minimumDensity,
        ),
      );
    }),
  ],
),