For Android :

• Go to project_folder/android/app/build.gradle
• Find the defaultConfig section update the minSdkVersion to the new version.
• run the flutter clean command.
• flutter pub get && flutter run

For IOS :

• Set MinimumOSVersion to 10.0 in ios/Flutter/AppFrameworkInfo.plist
• uncomment platform :ios, ‘10.0’ in ios/Podfile
• ios/Podfile should contains the following post install script:

post_install do |installer|
installer.pods_project.targets.each do |target|
flutter_additional_ios_build_settings(target)
target.build_configurations.each do |config|
config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '9.0'
end
end
end

Than you can run this command on your terminal.

  flutter clean 
        && rm ios/Podfile.lock pubspec.lock 
        && rm -rf ios/Pods ios/Runner.xcworkspace 

how can i set the required version of Android and Mac along with larger versions?

for example i want set requried version to Android 7 and IOS 10 and over version than these

Has anybody know how to do that?