SQL help needed to select certain rows using a WHERE CASE

My first post here, so please bear with me.

My Dataset

t1.c1    t1.c2   t2.c1   t2.c2   t2.c3   t3.c1
2551770  87772   87772   82272   TEST    P
2551770  87772   87772   K0328   TEST    P
2551770  99396   99396   99396   PREV    P
2809700  93000   93000   93000   ELEC    M
2809700  99397   99397   99397   PREV    M
2809700  99397   99397   G0439   PREV    M

Desired Output

t1.C1     t1.C2  t2.C1  t2.C2  t2.C3  t3.C1  t1.C3          
2551770   87772  82272  82272  TEST    P     82272 (from t1.C2)
2551770   99396  99396  99396  PREV    P     99396 (from t1.C2)
2809700   93000  93000  93000  ELEC    M     93000 (from t1.C2)
2809700   99397  99397  G0439  PREV    M     G0439 (from t2.C2)

I know this must use some sort of Case in the Where clause, but I am having a difficult time with the syntax. I need some help to get the desired output! I listed the logic below.

The logic is as follows:

1. If t3.C1 != 'M'
a. If t1.C2 = t2.C2 then select t1.C2
b. If t1.C2 != t2.C2 then do not retrieve this row
2. If t3.C1 = 'M'
a. If t1.C2 = t2.C2 And t2.C2 is not like 'PREV' then select t1.C2
b. If t1.C2 = t2.C2 And t2.C2 is like 'PREV' then do not retrieve this row
c. If t1.C2 != t2.C2 And t2.C2 is like 'PREV' then select t2.C2

>

And, I'm thinking of code like this, but I am getting lost with my cases:

Select Distinct*
From t1 Inner Join t2 On t1.C2 = t2.C1
Where  
  Case When t3.C1 != 'M' Then 
         Case When t1.C2 = t2.C2 Then t1.C2
              When t1.C2 != t2.C2 then /* do not retreive this row */
  Case When t3.C1 = 'M' Then
       Case When t1.C2 = t2.C2 And t2.C2 is not like 'PREV' Then t1.C2
        When t1.C2 = t2.C2 And t2.C2 is like 'PREV' then /* do not retreive this row */
        When t1.C2 != t2.C2 And t2.C2 is like 'PREV' Then t2.C2
End