public class class2 {
    public list<string> lststatename{get;set;}
    public list<string> lstrating{get;set;}
    public map<string, string> statemap {get;set;} 
    public list<string>selectedvalues{get;set;}
    public list<wrapperclass> listwrap {get;set;}
    public  class2(){
        string  jsonexample1 =  ' { "data": [ {"stateName": "Andrapradesh",  "value": "apx" }, { "stateName": "Telangana",  "value":"tsx"}, {"stateName": "Banglore",  "value": "bngx"} , {"stateName": "Maharastra",  "value":"mhx" }  ] } ';
        listwrap = new list<wrapperclass>();
        map<string,object>  metadatamap= (map<string,object>)json.deserializeuntyped(jsonexample1); +
            system.debug(metadatamap.keyset());
        system.debug(metadatamap.values());
        list<object>  values1= (list<object>)metadatamap.get('data');
        lststatename= new list<string>();
        lstrating= new list<string>();
        statemap= new map<String, string>(); 
        
        for(object parsed : values1){
            map<string,object>  values = (map<string,object>)parsed;
            string statename = string.valueof(values.get('stateName'));
            string value = string.valueof(values.get('value'));
            lststatename.add(statename);
            statemap.put(statename, value);
        }
        
        for(String s :statemap.keyset()){
            wrapperclass w = new wrapperclass();
            w.selected = false;
            w.statevalue = s;
            listwrap.add(w);
        }
    }
    public void test(){
        lstrating = new list<string>();
        for(wrapperclass wrap: listwrap){
            if(wrap.selected == true){
                lstrating.add(statemap.get(wrap.statevalue));
            }
        }
    }

public class wrapperclass{
    public boolean selected {get;set;}
    public string statevalue {get;set;}
}
}

<apex:page controller="class2">
  
  
  <apex:form >
  
  <ul style="list-style-type: none;">
 
  <apex:repeat value="{!listwrap}" var="a">
      <li ><apex:inputCheckbox value="{!a.selected}" /><label>{!a.statevalue}</label></li>
        </apex:repeat>
        </ul>
  
  
   <apex:commandButton action="{!test}" value="Test" reRender="fm" />
   
   
    <apex:outputLabel id="fm">
    
      the selected values are :
        <apex:repeat value="{!lstrating}" var="a">
            {!a}<br/>
        </apex:repeat>
    </apex:outputLabel>
  </apex:form>
  
  
</apex:page>