The growing demand for eco-friendly multifunctional nanomaterials has stimulated extensive research on sustainable synthesis approaches using plant-based resources. In this context, green synthesis has emerged as an effective alternative to conventional chemical methods due to its low toxicity, cost effectiveness, and environmental compatibility. The present study reports the phyto-mediated synthesis of functional multimetallic nanostructures using Caralluma stalagmifera extract as a natural reducing and stabilizing agent. The synthesized nanomaterial was characterized for studying its various physical, optical, morphological, compositional, and biological properties. The results of x-ray diffraction analysis revealed that the obtained nanomaterial was crystalline in nature and showed successful formation of its phases. FTIR results revealed the presence of functional groups responsible for nanoparticle reduction and stabilization, while UV–Visible spectroscopy demonstrated favorable optical absorption characteristics with semiconducting behavior. Raman spectroscopy further verified vibrational features and structural quality of the material. Surface morphology investigated through SEM showed irregularly distributed nanoscale grains with partial agglomeration, and EDX analysis confirmed the presence of major constituent elements including O, Na, Cl, K, Co, and Ag. Dielectric studies indicated frequency-dependent electrical behavior with promising dielectric constant and loss characteristics suitable for electronic applications. In addition, antimicrobial and antifungal investigations demonstrated effective inhibition against selected pathogenic microorganisms, confirming the biological potential of the synthesized samples. The integrated results establish a clear relationship between composition, structure, and multifunctional performance. Overall, this study highlights the capability of Caralluma stalagmifera mediated green synthesis for producing advanced nanomaterials with potential applications in biomedical coatings, sensors, environmental remediation, dielectric devices, and other emerging technologies.