This prospective randomized controlled trial aims to compare the clinical efficacy and safety of Percutaneous Nephrolithotomy (PCNL) and Retrograde Intrarenal Surgery (RIRS) for renal stones measuring 10-20 mm. The study specifically investigates whether the anatomical location of the stone (upper, middle, or lower calyx) influences the success rates and stone-free outcomes of these two surgical modalities. A total of 110 patients were randomized into two equal groups to evaluate primary endpoints, including stone-free rates at the 3-month follow-up, and secondary endpoints such as operative time and complication rates