$data_query ="SELECT  replace(ST_AsGeoJSON(geom),'','') As
geometry,taluk from s50k.aptaluk50soi2001";

{"type":"FeatureCollection","features":
[{"type":"Feature","geometry":"
{"type":"MultiPolygon","coordinates":
[[[[84.7316718809388,19.0302775870258],... etc.

<?php
$db = pg_connect("host=172.31.4.61 port=5432 dbname=geoserver user=postgres password=ndem$123") or die ("cant");

$data_query ="SELECT  replace(ST_AsGeoJSON(geom),'','') As geometry,taluk from s50k.aptaluk50soi2001";
//"select replace(replace(replace(ST_AsText(geom),'MULTIPOLYGON',''),'(','['),')',']') As geometry ,taluk FROM s50k.aptaluk50soi2001";

$data = pg_query($db,$data_query);
$geojson = array(
      'type'      => 'FeatureCollection',
      'features'  => array()
   );

   while($edge=pg_fetch_assoc($data)) {
     //  echo $edge['geometry'];
     //  $feature = $edge['geometry'];

      $feature = array(
            'type' => 'Feature',
            'geometry' => $edge['geometry'],
            'properties' => array(
             'taluk' => $edge['taluk']
                        ));

     array_push($geojson['features'], $feature);
   }
   echo json_encode( $geojson);
?>

{"type":"FeatureCollection","features":
[{"type":"Feature","geometry":{"type":"MultiPolygon","coordinates":
[[[[81.1303718809389,16.3617775870258],
[81.1277718809389,16.3566775870258],
[81.1187718809389,16.3511775870258],
[81.1058718809388,16.3404775870258],
[81.1055718809389,16.3355775870258]... etc.