Custom icon for a radio button

Right click on your drawable folder then->new->android xml file->choose root element "selector" then paste code below in the file:

<item android:drawable="@drawable/tire" android:state_checked="true"/>
  <item android:drawable="@drawable/tireinvert" android:state_checked="false"/>

then in xml of your radio button add this line:

android:button="@drawable/radio"

here radio is the selector xml file which we have created in the drawable folder

//first create custom_radio_search_location.xml file for custom radio in your drawable

<?xml version="1.0" encoding="utf-8"?>
   <selector xmlns:android="http://schemas.android.com/apk/res/android">
        <item android:state_checked="true"
          android:drawable="@drawable/invite_radio_check" />
        <item android:state_checked="false"
          android:drawable="@drawable/invite_radio_uncheck" />
   </selector>

//than use this custom_radio_search_location.xml in your layout

<RadioGroup
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:weightSum="3" >

    <RadioButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:background="@android:color/transparent"
        android:button="@drawable/custom_radio_search_location"
        android:checked="true"
        android:text="A"
        android:textColor="@android:color/black" />

    <RadioButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:background="@android:color/transparent"
        android:button="@drawable/custom_radio_search_location"
        android:text="B"
        android:textColor="@android:color/black" />

    <RadioButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:background="@android:color/transparent"
        android:button="@drawable/custom_radio_search_location"
        android:text="C"
        android:textColor="@android:color/black" />
</RadioGroup>