The following approaches are used to customize the Autocomplete component in MUI in React:  
1. Custom Render Input 
   <Autocomplete
     options={options}
     renderInput={(params) => <TextField {...params} label="Custom Autocomplete" />}
   />
2. Custom Styling (Using `sx` or `styled`)  
   <Autocomplete
     sx={{ width: 300, backgroundColor: 'lightgray' }}
     options={options}
   />
3. Custom Option Rendering
   <Autocomplete
     options={options}
     renderOption={(props, option) => (
       <li {...props} style={{ color: 'red' }}>{option.label}</li>
     )}
   />
4. Controlled Component
   const [value, setValue] = useState(null);
   <Autocomplete
     value={value}
     onChange={(event, newValue) => setValue(newValue)}
     options={options}
   />