Clearly, the letters in the word SIKKIM are moved alternately one step forward and one step backward to obtain the letters of the code.
(S → T), (I ← H), (K → L), (K ← J), (I → J), (M ← L)
So, in TRAINING,
T will be coded as U, (R as Q), (A as B), (I as H), (N as O), so on.
Thus, the code becomes UQBHOHOF.
Hence, the answer is (b).