Update Apex Class as below

APEX CLASS :

global with sharing class iDealPageRedirectExtn {

    public static Integer count{get; set;}
    public static Integer count2{get; set;}
    public static Integer count3{get; set;}
    public static Integer count4{get; set;}
    public iDealPageRedirectExtn(ApexPages.StandardController controller){
        Account account = (Account) controller.getRecord();
        String accountId = Account.Id;
            //String accountId = ApexPages.CurrentPage().getParameters().get('id'); // On Standard controller no need to take Id from getParameters method, use the Controller.getRecord instead.
        if(accountId!=null){
            System.debug(count+' '+count2+' '+count3+' '+count4);
            count     =     0;
            count2  =     0;
            count3    =      0;
            count4    =     0;
               count =[select count() from Agency_Info__c where Account__c= :accountId and Recordtype.Name='Distribution' limit 1];             
             count2 =[select count() from Agency_Info__c where Account__c=:accountId and PCC__c!='' and Recordtype.Name='GDS' limit 1];             
             count3 =[select count() from Agency_Info__c where Account__c in (select Primary_Account__c from Account_Relation__c where Related_Account__c=:accountId and Active__c=TRUE) and PCC__c!='' limit 1];             
             count4 =[select count() from Contract__c where Account__c=:accountId];           
            System.debug(count+' '+count2+' '+count3+' '+count4);
            }
        
    }    
}

Test Class
===============

@isTest
private class iDealPageRedirectExtnTest {
    @istest
    private static void testmethod1()
    {    
        Accountexp1.count = 0;
         Accountexp1.count2 = 0;
         Accountexp1.count3 = 0;
         Accountexp1.count4 = 0;
         Account ac = new Account();
         ApexPages.StandardController std = new ApexPages.StandardController(ac);
        Accountexp1 exp = new Accountexp1(std);
        
    }
}