The export performance of defence products has become a significant indicator of technological capability, industrial strength, and geopolitical influence in the global economy. This study examines the export performance of defence products in BRICS countries during the period 2015-16 to 2025-26. Defence exports are a key indicator of technological advancement and economic strength. The study uses secondary data and applies data mining techniques through WEKA, including classification, clustering, regression, and association rule mining. Key variables considered include export value, gross domestic product (GDP), research and development (R&D) expenditure, and military spending. To derive meaningful insights, data mining techniques are applied using the WEKA (Waikato Environment for Knowledge Analysis) tool. The study aims to analyze trends, compare country-wise performance, and identify key determinants influencing defence exports within the BRICS bloc. The study highlights that R&D expenditure and military spending significantly influence export performance.