<?php

    $array1 = array(name=>'JK',age=>'20',place=>'India',year=>array(marks1=>array(sub1=>50,sub3=>70,sub7=>65,sub5=>75,sub4=>35), marks2=>array(sub8=>50,sub10=>70,sub12=>75,sub9=>35,sub11=>65)));

    function sorter($a,$b)
    {
        $array2 = array(name=>1,year=>2,age=>3,place=>4,sub1=>5,sub3=>6,sub4=>7,sub5=>8,sub7=>9,sub8=>10,sub9=>11,sub10=>12,sub11=>13,sub12=>14);
        return $array2[$a] > $array2[$b];

    }

    uksort($array1, sorter);
    var_dump($array1);

array(4) {
  ["name"]=>
  string(2) "JK"
  ["year"]=>
  array(2) {
    ["marks1"]=>
    array(5) {
      ["sub1"]=>
      int(50)
      ["sub3"]=>
      int(70)
      ["sub7"]=>
      int(65)
      ["sub5"]=>
      int(75)
      ["sub4"]=>
      int(35)
    }
    ["marks2"]=>
    array(5) {
      ["sub8"]=>
      int(50)
      ["sub10"]=>
      int(70)
      ["sub12"]=>
      int(75)
      ["sub9"]=>
      int(35)
      ["sub11"]=>
      int(65)
    }
  }
  ["age"]=>
  string(2) "20"
  ["place"]=>
  string(5) "India"
}