A number of languages distinguish between maternal and paternal aunts and uncles; English is not one of them, but Persian can be (though it doesn’t have to be). “Uncle” regardless of the side of the family can be عَمّو (ʿammū, pl. عَمّوها ʿammūhā), but this can also specifically mean paternal uncle, with maternal uncle being دایی (dāyī). “Aunt” may be عَمّه (ʿammah, pl. عَمّهها ʿammah-hā), but this can also be specifically paternal aunt, with maternal aunt being خاله (khālah).
One thing to bear in mind is that we’re talking about blood relatives only; in-laws are another entry.