Which of the following sentences is correct?
If you are caught stealing you will be fined.
If you were caught stealing you will be fined.
The first is fully grammatical, the second is at least dubious. However a third possibility is grammatical:
The difference between your first example and mine is that the "... were ... would" is usually said to be hypothetical; but in fact these are both hypothetical.
There is a difference: the "If you are ... " implies that you are stealing, or that you are definitely intending to do so. "If you were ... " carries no such implication.
Foreign learners of English are taught that If you are caught stealing you will be fined is the First Conditional and that If you were caught stealing you would be fined is the Second Conditional. The First Conditional describes a situation that might very well happen. The Second Conditional describes a situation that is much less likely to happen. There is a Third Conditional, If you had been caught stealing you would have been fined. Of the three only this describes a truly hypothetical situation.