I was write  a test class, but i am getting code coverage 54% only. 

public class abhinav {


    private Apexpages.StandardController controller;

    Public string selectedPRC{get;set;}
    //Public callRedirect();

    String Id;
    public abhinav(ApexPages.StandardController controller) {
        Id = ApexPages.currentPage().getParameters().get('id');
    }


    //Our collection of the class/wrapper objects cContact
    public List<cContact> contactList{get;set;}

    //This method uses a simple SOQL query to return a List of Contacts
    public List<cContact> getContacts(){
        
        
            contactList = new List<cContact>();
            for(Contact c: [select Id, firstName, lastname, Pcp_Roles__c from Contact where AccountId=:Id and Contact_Portal_ID__c!=null and Portal_User_Status__c='active'])
            {
                
                contactList.add(new cContact(c));
            }
       
        return contactList;
        
    }

    // This is our wrapper/container class. A container class is a class, a data structure, or an abstract data type whose instances are collections of other objects. In this example a wrapper class contains both the standard salesforce object Contact and a Boolean value
    public class cContact {
        public Contact con {get; set;}
        public Boolean selected {get; set;}

        public cContact(Contact c) {
            con = c;
            //selected;    
        }
    }
    
    
    public List<SelectOption> getPRCRoles()
        {
                List<SelectOption> options = new List<SelectOption>();
                
               Schema.DescribeFieldResult fieldResult =
             Contact.Pcp_Roles__c.getDescribe();
             
               List<Schema.PicklistEntry> ple = fieldResult.getPicklistValues();
                
               options.add(new SelectOption(  'none','-- Select One --'));
               for( Schema.PicklistEntry f : ple)
               {
                  options.add(new SelectOption( f.getValue(), f.getLabel()));
               }
            return options;
            //System.debug('Options --'+options);
        }    
        
        
    Public Pagereference save(){
                                            

                    // this.controller.save();
                    System.debug('What is selected PRC'+selectedPRC);
                    if(selectedPRC.equalsIgnoreCase('none'))
                    {
                        System.debug('I got here');
                        ApexPages.addmessage(new ApexPages.message(ApexPages.severity.ERROR,'Please select a PCP role.'));
                        
                        return null;
                    }

            List<contact> selectedcontacts=new List<contact>();
           

            
                    for(cContact cCon: contactList) {
                    if(cCon.selected == true) {
                        selectedContacts.add(cCon.con);
                            }
                    }
                    System.debug('What is selected PRC and contact size-----'+selectedPRC);
                    System.debug('What is selected PRC and contact size-----'+selectedContacts.size());
                    if(selectedPRC != 'none' && selectedContacts.size() == 0)
                    {
                        ApexPages.addmessage(new ApexPages.message(ApexPages.severity.ERROR,'Select atleast one contact'));
                        return null;
                    }
            
                    System.debug('These are the selected Contacts...'+selectedContacts);
                    for(Contact con: selectedContacts) {
                    system.debug(con);
                    
                        if(selectedPRC != 'none')
                        {
                        if(con.Pcp_Roles__c==null)
                                {
                                        con.Pcp_Roles__c=selectedPRC+';';
                                 }       
                        else {                                
                                    if(!con.Pcp_Roles__c.contains(selectedPRC))
                                    {  
                                        con.Pcp_Roles__c+=';'+selectedPRC;
                                    }
                               }
                               }      
                    }

            
            try{
                    update selectedcontacts;
                    callRedirect();
                    }catch(Exception e){
                          ApexPages.addmessage(new ApexPages.message(ApexPages.severity.ERROR,'Something happened: your action did not complete. Refresh the page and ry again.'));  
                    }
            
            return null;
            
                    
    }  
    
    Public Pagereference callRedirect(){
            System.debug('What is option '+selectedPRC);
            PageReference p = new PageReference('/' + Id);
            System.debug('What is completepagereferece '+p);
            p.setRedirect(true);
            return p;
                    
    }  

@istest
public static void test_abhinav()
    {
        Account a = new Account(id='0019000000LFNec');
        ApexPages.StandardController sc = new ApexPages.standardController(a);
       
        abhinav testcls = new abhinav(sc);
        List<cContact> aList = testcls.getContacts();
        testcls.ContactList=aList;
    
        List<SelectOption> aPRC = testcls.getPRCRoles();
      
        testcls.selectedPRC='none';
       // system.assertEquals(testcls.save(),null);
        for(SelectOption anOption : aPRC)
        {
            testcls.selectedPRC=String.valueOf(anOption);
            for(cContact con : testcls.ContactList)
            {
                con.selected=true;
            }
            system.assertEquals(testcls.save(),null);
        }

        
       // system.assertEquals(testcls.callRedirect(),null);
    }
}

<apex:page standardcontroller="Account" extensions="abhinav">
        
      <apex:form >
        <apex:pageMessages id="error"></apex:pageMessages>
        <apex:pageBlock title="GPRT Price Book Allocation" mode="edit" >
            <br></br>
            
            <apex:pageBlockButtons >
                 <apex:commandButton value="     Ok      " action="{!save}" rerender="Selected_PBS,error"/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
                <apex:commandButton value="     Cancel      " action="{!Cancel}"/>
            </apex:pageBlockButtons>
        

             
             <apex:outputText style="font-style:regular; font-weight:Regular; font-size:14px; font-family:Helvetica" value="Add PCP role" ></apex:outputText>
             <br></br>
                                                    
             <apex:selectList size="1" value="{!selectedPRC}" id="PRCoptions" style="width: 300px;"   Title="Add PCP Role">
             <apex:selectOptions value="{!PRCRoles}"/>
             </apex:selectList>
             <br></br><br></br><br></br>

                
                <apex:pageBlockTable value="{!contacts}" var="c" id="Selected_PBS">
                    <apex:column ><apex:inputCheckbox value="{!c.selected}" id="checkedone"/></apex:column>
                    <apex:column value="{!c.con.firstName}" />
                    <apex:column value="{!c.con.lastname}" />
                    <apex:column value="{!c.con.Pcp_roles__c}" headerValue="PCP Roles (Read Only)"/>
                </apex:pageBlockTable>
                
            </apex:pageBlock>
          
        </apex:form>
       
<script>
function checkAll(cb)
{
var inputElem = document.getElementsByTagName("input");
for(var i=0; i<inputElem.length; i++)
{
if(inputElem[i].id.indexOf("checkedone")!=-1)
inputElem[i].checked = cb.checked;
}
}   

function checkAll(cb,cbid)
        {
            var inputElem = document.getElementsByTagName("input");                     
            for(var i=0; i<inputElem.length; i++)
            {             
                 if(inputElem[i].id.indexOf(cbid)!=-1){                                        
                    inputElem[i].checked = cb.checked;
                }
            }
        }
 
</script>
</apex:page>