Set Group wise rank using Rank function in SQL Server

how to get the correct and accurate rank?

I have a data like this tblSetMarks

now i want to get output like this in sql server

where as my query is showing me wrong rank

            SELECT SPic,SessionName,ExamType,fa.AdmissionNo,ReferenceNo,SName,FName,FPhone,AcademicName,ClassName,SectionName,SubjectName,Max,Mark 
                ,Round((Mark) * 100/ (Max),1) as SubPer
                ,dense_rank() over(partition BY SUM(Max) order by SUM(Mark) DESC )  AS SubPos
                ,(CASE WHEN  Round((SUM(Mark)) * 100/ SUM([Max]),1) >= 90 THEN 'A+'
                WHEN  Round((SUM(Mark)) * 100/ SUM([Max]),1) >= 80 THEN 'A'
                WHEN  Round((SUM(Mark)) * 100/ SUM([Max]),1) >= 70 THEN 'B'
                WHEN  Round((SUM(Mark)) * 100/ SUM([Max]),1) >= 60 THEN 'C'
                WHEN  Round((SUM(Mark)) * 100/ SUM([Max]),1) >= 50 THEN 'D'
                WHEN  Round((SUM(Mark)) * 100/ SUM([Max]),1) >= 40 THEN 'E'
                ELSE 'FAIL' END ) AS Grade
 
                ,(CASE WHEN  Round((SUM(Mark)) * 100/ SUM([Max]),1) >= 90 THEN 'OutStanding'
                WHEN  Round((SUM(Mark)) * 100/ SUM([Max]),1) >= 80 THEN 'Excellent'
                WHEN  Round((SUM(Mark)) * 100/ SUM([Max]),1) >= 70 THEN 'Very Good'
                WHEN  Round((SUM(Mark)) * 100/ SUM([Max]),1) >= 60 THEN 'Good'
                WHEN  Round((SUM(Mark)) * 100/ SUM([Max]),1) >= 50 THEN 'Satisfactory'
                WHEN  Round((SUM(Mark)) * 100/ SUM([Max]),1) >= 40 THEN 'Work Hard'
                ELSE 'FAIL' END ) AS Remarks
 
                FROM tblSetMarks as fa
                            inner join tblSession as ses on fa.SessionID=ses.SessionID
                            inner join tblSetExam as st on fa.SetExamID=st.SetExamID
                            inner join tblStdReg as sr on fa.AdmissionNo=sr.AdmissionNo
                            inner join tblAssignSubjects as fh on fa.SubjectID=fh.ASID inner join tblDefSubject as df on fh.SubjectID=df.SubjectID
                            inner join tblAcademicYear as ay on sr.YearID=ay.YearID
                            inner join tblDefClass as dc on sr.ClassID=dc.ClassID
                            inner join tblDefSection as ds on sr.SectionID=ds.SectionID --where fa.SessionID=@SesId and fa.SetExamID=@EId and fa.ClassID=@CId and fa.SectionID=@SId                      
                          
                            group by SPic,SessionName,ExamType,fa.AdmissionNo,ReferenceNo,SName,FName,FPhone,AcademicName,ClassName,SectionName,SubjectName,Max,Mark order by AdmissionNo,SubjectName desc;