Barring me having botched order here since I don't have anything to test against this should be pretty colse to what you are after.

SELECT

 ST.student_id,

 ST.last_name + ',  ' + ST.first_name + '(' + ST.grade + ')' AS [Name],

 R.program_provider_activity_id, PPA.program_activity_name + '                                                    Currently Reg : ' + (CASE WHEN (R.registration_is_active = 1) THEN 'Yes' ELSE ' No' END) AS program_activity_name,

 R.program_id,

 SUM(datediff(hh, s.session_start_time, s.session_end_time)) TotalHours,

 COUNT(DISTINCT (session_start_time)) TotalDays,

 COUNT(DISTINCT (datepart(ww, session_start_time))) TotalWeeks

FROM

 dbo.ProgramProviderActivity PPA

INNER JOIN

 dbo.Registration R

INNER JOIN

 dbo.Student ST

ON

 ST.student_id = R.student_id

ON

 PPA.program_provider_activity_id = R.program_provider_activity_id

LEFT JOIN

 dbo.Attendance A

 INNER JOIN

  dbo.Session S

 ON

  S.program_provider_activity_id = R.program_provider_activity_id AND

  S.program_id = R.program_id AND

  S.Session_id = A.Session_id

ON

 A.attendence_status = 1 AND

 A.student_id = ST.student_id

GROUP BY

 ST.student_id,

 ST.last_name + ',  ' + ST.first_name + '(' + ST.grade + ')',

 R.program_provider_activity_id, PPA.program_activity_name + '                                                    Currently Reg : ' + (CASE WHEN (R.registration_is_active = 1) THEN 'Yes' ELSE ' No' END),

 R.program_id

-- Noter may have to do some work still to get Order By right because of Group By

ORDER BY

 ST.last_name + ' ' + ST.first_name,

 ST.grade