Correct option is D
In this question following logic is followed-
[(1st)2 + (2nd)3] = 3rd number
First row: 15, 3, 252 → [(15)2 + (3)3] = 225 + 27 = 252
Second row: 11, 5, 246 → [(11)2 + (5)3] = 121 + 125= 246
Similarly,
Third row: 9, 6, ? → [(9)2 + (6)3] = 81 + 216= 297
Therefore, the correct option is (d).