YOU SAID:

I will make him an offer he cannot refuse.

INTO JAPANESE

私は彼に彼が拒絶できない申し出をするつもりです。

BACK INTO ENGLISH

I will offer him an offer he can not refuse.

INTO JAPANESE

私は彼が拒絶できない申し出を彼に申し出るでしょう。

BACK INTO ENGLISH

I will offer him an offer he can not refuse.