Node js callback issue

In my NodeJS application, I am building an API that first fetches all tarrifs name from tarrifs collection then based on all those tarrifs I want to return the counts of these tariffs allocated to users I tried the below-given code

router.get('/getTarrifDetails', (req,res,next) => {
     result=[];
     tname=[];
     counts=[];
 Tarrif.find().distinct('tarrif_type', (err,docs) => {
   docs.forEach((ele) => {
     tname.push(ele);

     User.countDocuments({tarrif_type:ele}, (uerr,usr) => {
         counts.push(usr);
     });

     result.push(ele);
 });

 result.push(counts);

});

});

When I console.log(result) it only shows one array of tarrif_type and other array is empty

#node-js