If in a coding system, FIXED is coded as 86 and COMPANY is coded as 1…

1   2    3    4   5    6   7     8    9  10  11  12  13

 A   B   C    D   E    F   G    H    I    J    K    L   M

 ↓    ↓    ↓    ↓    ↓     ↓   ↓    ↓     ↓   ↓    ↓    ↓    ↓

 Z   Y    X   W   V    U   T    S    R   Q   P    O   N

26  25  24  23  22  21  20  19  18  17  16  15  14

**********************************************************

The pattern here is;

FIXED as 86,

(opposite of FIXED is URCVW)

Now, sum of positional value of URCVW and -1

21+18+3+22+23 -1

86

And,

COMPANY as 101,

(opposite of COMPANY is XLNKZMB)

Now, sum of positional value of XLNKZMB and -1

24+12+14+11+26+13+2 -1

101

Similarly,

INTERIM  as ....?,

(opposite of INTERIM is RMGVIRN)

Now, sum of positional value of RMGVIRN and -1

18+13+7+22+9+18+14 -1

100