PAGE:

<apex:page>
 <apex:form>
  <!-- HERE IS THE SELECTION LIST -->
  <apex:outputPanel id="verslist">
   <apex:actionstatus id="verstatus" startText="(Activating...)">
    <apex:facet name="stop">
     <apex:pageBlock title="Versionlist">
      
      <apex:pageBlockButtons location="top">
       <apex:outputPanel id="button">
        <apex:commandButton alt="Activate" value="Activate" action="{!activation}" status="verstatus" rerender="verslist" />
       </apex:outputPanel>
      </apex:pageBlockButtons>
      
      <!-- vVer records from wrapper class -->
      <apex:pageBlockTable value="{!versions}" var="v" id="table">
       <apex:column>
        <apex:outputPanel id="checkboxes">
         <apex:inputCheckbox value="{!v.selected}" onclick="deselectOther(this)" />
         <apex:actionSupport event="onclick" action="{!enable}"rerender="out,button,checkboxes" status="status2" />
         <apex:param name="checked" value="{!v.ver.Id}" />
        </apex:outputPanel>
       </apex:column>
       <apex:column value="{!v.ver.Name}" />
       <apex:column value="{!v.ver.Version_Number__c}" />
       <apex:column value="{!v.ver.Description__c}" />
       <apex:column value="{!v.ver.Active__c}" />
      </apex:pageBlockTable>
      
     </apex:pageBlock>
    </apex:facet>
   </apex:actionstatus>
  </apex:outputPanel>
 </apex:form>

 <apex:outputPanel id="out">
  <apex:actionstatus id="status2" startText="Refreshing...">
   <apex:facet name="stop">
    <apex:outputPanel rendered="{!dpanel}">
     <apex:pageBlock title="Details">
      <apex:pageBlockTable value="{!products}" var="p" id="restable">
       <apex:column value="{!p.Product__c}" />
       <apex:column value="{!p.Quantity__c}" />
       <apex:column value="{!p.Price__c}" />
      </apex:pageBlockTable>
     </apex:pageBlock>
    </apex:outputPanel>
   </apex:facet>
  </apex:actionstatus>
 </apex:outputPanel>
</apex:page>

Controller:

public class tenderPage {
   
 public PageReference configure2() {

  .... 
 }
   
 //Global utility variable
 public Boolean askPageSelections = false;
 public ID selectedVersion {get; set;}
  
  
 //--------------------------------- BUTTON / PANEL ENABLERS --------------------

 // ***************** ENABLE IS HERE   ***********************  
 // pageref function called in event to activate panels / buttons
 public PageReference enable() {
  selectedVersion = System.currentPageReference().getParameters().get('checked');

  for(vVersion v : getVersions()){
   if(v.ver.Id == selectedVersion){
    v.selected == true;
   }else{
    v.selected == false;
   }
  }
  return null;
 }


//--------------------------------- END BUTTON / PANEL ENABLERS END-------------------- 

 public tenderPage(ApexPages.StandardController stdController) {
  this.tend = (Tender__c)stdController.getRecord();
 }

 // *** Get the products for the selected version ***
 public List<Product_offering__c> getProducts() {

  //something like this:
  .... List<Product_offering__c> prods = [select Id, Product__c, Quantity__c, Price__c from Product_offering__c where VersionID = :selectedVersion]
   
 return prods;
 }
        
        
// ***************** ACTIVATION IS HERE   ***********************
 public pageReference activation() {

  List <Version__c> vers = new List <Version__c>(); 

  for(vVersion vver : getVersions()){
   if(vver.selected == true){
    vers.add(vver.ver);
   }
  }

  if(!vers.isEmpty())
  update vers;

  return null;
 }
  
  
// ------------------------------ VERSION HANDLING ------------------------------------------------
         

 //Collection of the class/wrapper objects  
 public List<vVersion> versionList {get; set;}

 public List<vVersion> getVersions() {

 if(versionList == null){ 
  Boolean b = false;

  // Instantiate new version list
  versionList = new List<vVersion>();

  for (Version__c v : [select Id, Name, Active__c, Description__c, Version_Number__c from Version__c where Tender__c = :tend.Id]){
   versionList.add(new vVersion(v,b));
  }
 }

 return versionList;
 }
       

// ----------------  wrapper class --------------------------------     
    
        public class vVersion{
                
         ...
        }
        
}