In a certain code, MONKEY is written as XDJMNL. How is TIGER written in that code?

QDFHS

The following table shows the position values of the alphabets:

We can also memorize the alphabets so that we do not do any calculation mistakes and also reduce the time to solve answers: 

The pattern which has been observed is:

6th letter becomes 1st (After deducting 1), 5th letter becomes 2nd (After deducting 1), 4th letter becomes 3nd (After deducting 1), 3rd letter becomes 4th (After deducting 1), 2nd letter becomes 5th (After deducting 1) and 1st letter becomes last(After deducting 1)