Along with title and snippet how to add extra data to marker?

While @worawee.s's will work perfectly fine, there is a more elegant solution that can allow you to add additional informations to a Marker object. So to solve this, you can use Marker's setTag (Object tag) method:

You can use this property to associate an arbitrary Object with this marker. For example, the Object can contain data about what the marker represents. This is easier than storing a separate Map. As another example, you can associate a String ID corresponding to the ID from a data set.

Not the best solution but this what I do in my application.

create markersMap as a private field in your activity/fragment.

private Map<Marker, ExtraDataObj> markersMap = new HashMap<Marker, ExtraDataObj>();

When you generate marker also put the marker and extra data in your markersMap

ExtraDataObj extraDataObj = new ExtraDataObj();
// extract and store all data you want in the extraDataObj
....
...
..
Marker marker = gMap.addMarker(new MarkerOptions()
                        .title(e.getString("name"))
                        .snippet(
                                e.getString("LS")+""+e.getString("ph") )
                        .position(new LatLng(lng1, lat1))
                        .icon(BitmapDescriptorFactory
                                .fromResource(R.drawable.pmr)));
markersMap.put(marker, extraDataObj);

in your onInfoWindowClick get extra data from the markersMap

ExtraDataObj extraDataObj = markersMap.get(arg0)