Answer:
The same structure, in indirect or reported form, would be:
The principal will say that rules have to be followed at any cost.
Explanation:
<u>When reporting what someone said, we must change the verb tenses according to when the line was said. If there are any pronouns in the sentence, those may also need to be changed to match the speaker - for instance, if a man said something about himself, we should change "I" for "he". We also change time expressions, such as substituting "today" for "that day".</u>
<u>Not much changes in the sentence we are transforming here since the line inside the quotation marks does not present time expressions or pronouns. Another reason for that is the verb tense. Because it is "will say", which is a future, we do not have to change the verb tense inside the quotation marks.</u>
Just to make it clearer, imagine that the principal already said that: The principal said, "Rules have to be followed at any cost." Now the tense is in the past, "said". In this case, we should also change the tense inside the quotation marks. It would be: The principal said that rules had to be followed at any cost.
