What are the rules for reporting conditional sentences in indirect speech?

The rules for reporting conditional sentences in indirect speech are as follows:

1. If the reporting verb is in the past tense, the verb in the conditional clause remains unchanged.
Example: He said, "If I had enough money, I would buy a new car." (Direct speech)
He said that if he had enough money, he would buy a new car. (Indirect speech)

2. If the reporting verb is in the present tense, the verb in the conditional clause changes to the past tense.
Example: She says, "If I see him, I will tell him the news." (Direct speech)
She says that if she saw him, she would tell him the news. (Indirect speech)

3. If the reporting verb is in the present perfect tense, the verb in the conditional clause changes to the past perfect tense.
Example: They have said, "If we have time, we will visit the museum." (Direct speech)
They have said that if they had had time, they would have visited the museum. (Indirect speech)

4. If the reporting verb is in the past perfect tense, the verb in the conditional clause changes to the past perfect tense.
Example: He had mentioned, "If I had known, I would have helped." (Direct speech)
He had mentioned that if he had known, he would have helped. (Indirect speech)

It is important to note that when reporting conditional sentences in indirect speech, the word "if" is usually replaced with "whether" or omitted altogether. Additionally, the pronouns and adverbs may need to be changed to reflect the shift in perspective.