Grouping in Elastic Search

I have a problem with doing grouping operation in elastcicSearch.

Actually, i have 3 fields in my document. that is as under:

Id ExceptionType  ReleaseYear

Now I want to do grouping on ExceptionType and ReleaseYear and count it in "ResultCount".

I tried this one but it is not working:

.Aggregations(a => a
            .ValueCount("ResultCount", c => c
                .Field(p => p.availInstanceId)
                .Field(p=> p.releaseYear)
            ))
             .Aggregations(a => a
                .Terms("ExceptionType", st => st
                    .Field(o => o.ExceptionType)
                    .Size(10))).Size(5)
             .Aggregations(aa => aa
                    .Max("ReleaseYear", m =>  m
                        .Field(o => o.ReleaseYear)
                    ))
           );

Please give a solution for this problem as soon as possible. thank you.