FGH : JKL :: PQR : ?
FGH : JKL :: PQR : TUV
There is sequence in left hand side part. F-G-H are three consecutive letters of English Alphabets, after skipping ‘I’ we get next three consecutive letter J-K-L.
On right-hand side we have P-Q-R in the same manner so next set of letters will be (skip ‘S’ letter) TUV.