Cement, aggregates, and water are the three main components of concrete, the strongest construction material. The growth of infrastructure in the building industry has led to a greater use of natural river sand on a worldwide scale. Government restrictions on river sand extraction had resulted in unlawful mining and raised the cost of sand. The use of M-sand as a fine aggregate has expanded as a result of the shortage of river sand. Utilising M-sand is made possible by its accessibility, affordable transportation, and controllable size as needed for grading. Only a variety of cutting-edge tactics, including smart material selection, contemporary techniques for eco-efficient operations, and trash recycling, can lead to the building industry's sustainable development. This research compares the use of GGBS as a partial substitute for cement in Natural River Sand and M-Sand when added in various amounts (0%, 5%, 10%, 15%, 20%, 25%). To ascertain the ideal proportion of GGBS replacement in cement using both River sand and M-Sand as fine aggregate in concrete, an experimental investigation was carried out. Concrete's compressive strength, splitting tensile strength, flexural strength, and elastic modulus were all tested, and the results for all different mix types were compared. According to the findings, 20% of GGBS replaced in M-Sand concrete exhibits more strength than 20% of GGBS replaced in concrete made with natural river sand.