SQL Server 2022

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CREATE TABLE tablename 
(
    RowNum INT NOT NULL IDENTITY(1,1),
    V1	int,    I1	int,    T1	int,    V2	int,    I2	int,    T2	int,
    V3	int,    I3	int,    T3	int,    V4	int,    I4	int,    T4	int
);

INSERT INTO tablename (V1, I1, T1, V2, I2, T2, V3, I3, T3, V4, I4, T4) VALUES
	(15, 1, 1, 12, 1, 1, 22, 1, 3, 0, 0, 0),
	(15, 1, 1, 22, 2, 3, 0, 0, 0, 16, 1, 1),
	(15, 1, 1, 15, 2, 1, 0, 0, 0,  0, 0, 0),
	(0, 0, 0, 0, 0, 0, 18, 2, 1, 0, 0, 0);

SELECT * FROM tablename

Select RowNum, 
     CASE T1 WHEN 1 THEN CASE WHEN I1 in (1,2) THEN V1 ELSE 0 END
             ELSE 0 END +  
     CASE T2 WHEN 1 THEN CASE WHEN I2 in (1,2) THEN CASE I1+I2 WHEN 3 THEN 0 ELSE V2 END  ELSE 0 END
             ELSE 0 END +  
     CASE T3 WHEN 1 THEN CASE WHEN I3 in (1,2) THEN CASE I1+I2+I3 
                                                    WHEN 3 THEN 0 
                                                    WHEN 5 THEN 0 
                                                    ELSE V3 END ELSE 0 END
             ELSE 0 END +  
     CASE T4 WHEN 1 THEN CASE WHEN I4 in (1,2) THEN CASE I1+I2+I3+I4 
                                              WHEN 3 THEN 0 
                                              WHEN 5 THEN 0   
                                              WHEN 7 THEN 0 
                                              ELSE V4 END ELSE 0 END
             ELSE 0 END   AS SUM
FROM  tablename
WHERE (T1=1 AND I1 in (1,2))
    or (T1=1 AND I2 in (1,2))
  or (T3=1 AND I3 in (1,2))
  or (T4=1 AND I4 in (1,2))

RowNum	V1	I1	T1	V2	I2	T2	V3	I3	T3	V4	I4	T4
1	15	1	1	12	1	1	22	1	3	0	0	0
2	15	1	1	22	2	3	0	0	0	16	1	1
3	15	1	1	15	2	1	0	0	0	0	0	0
4	0	0	0	0	0	0	18	2	1	0	0	0

RowNum	SUM
1	27
2	31
3	15
4	18

RowNum	V1	I1	T1	V2	I2	T2	V3	I3	T3	V4	I4	T4
1	15	1	1	12	1	1	22	1	3	0	0	0
2	15	1	1	22	2	3	0	0	0	16	1	1
3	15	1	1	15	2	1	0	0	0	0	0	0
4	0	0	0	0	0	0	18	2	1	0	0	0

RowNum	V1	I1	T1	V2	I2	T2	V3	I3	T3	V4	I4	T4
1	15	1	1	12	1	1	22	1	3	0	0	0
2	15	1	1	22	2	3	0	0	0	16	1	1
3	15	1	1	15	2	1	0	0	0	0	0	0
4	0	0	0	0	0	0	18	2	1	0	0	0

RowNum	V1	I1	T1	V2	I2	T2	V3	I3	T3	V4	I4	T4
1	15	1	1	12	1	1	22	1	3	0	0	0
2	15	1	1	22	2	3	0	0	0	16	1	1
3	15	1	1	15	2	1	0	0	0	0	0	0
4	0	0	0	0	0	0	18	2	1	0	0	0