Add rinsed rice, water (or broth), and salt to Instant Pot. Stir briefly.
Lock lid into place and set pressure valve to “Sealing.” Select “Manual” or “Pressure Cook” on High for 3 minutes (white rice) or 22 minutes (brown rice).
When timer goes off, allow natural release for 10 minutes, then quick release any remaining pressure.
Remove lid. Fluff rice with a fork. Immediately stir in lime juice, lime zest, cilantro, and cumin. Season with pepper to taste.
Let sit 2-3 minutes so rice absorbs the lime, then serve.