Is it grammatically correct to say you will reach the point where can leave Iran?

The correct sentence is "you will reach the point where you can leave Iran."

The verb "can" is used to express ability or permission. In this sentence, it is used to express ability. The subject of the sentence is "you", so the verb must be "can". The infinitive "to leave" is used after "can" to express the action that the subject is able to do.