YOU SAID:

I informed the gate office person he will do the needful

INTO JAPANESE

私はゲートオフィスの人に彼が必要なことをすると伝えた

BACK INTO ENGLISH

I told the gate office man that he would do what was necessary.

INTO JAPANESE

私はゲートオフィスの男に、彼が必要なことをすると言った.

BACK INTO ENGLISH

I told the man at the gate office that he would do what was necessary.

INTO JAPANESE

私はゲートオフィスの男性に必要なことをすると言った.

BACK INTO ENGLISH

I told the man at the gate office that I would do what was necessary.

INTO JAPANESE

私はゲートオフィスの男性に、必要なことはすると言った.

BACK INTO ENGLISH

I told the man at the gate office that I would do what was necessary.