YOU SAID:

My brother Rohan is 13 this year and he will be entering year 9

INTO JAPANESE

私の兄弟Rohanは今年13歳で、彼は9歳になります。

BACK INTO ENGLISH

My brother Rohan is 13 years old this year, he will be nine years old.

INTO JAPANESE

私の兄Rohanは今年13歳です、彼は9歳になります。

BACK INTO ENGLISH

My brother Rohan is 13 years old this year, he will be nine years old.