The production and consumption of energy in all walks of life is moving towards a greener and more sustainable mix of energy sources away from the traditional sources of coal and gas. With this shift, more renewable energy is expected to be integrated into the grid replacing conventional synchronous generators. In such conditions, the stability of the grid becomes a major concern due to the lack of inertia with the loss of base load generators. As a result, there is an urgent need to develop flexible solutions like Battery Energy Storage System (BESS) to provide ancillary services. Current research tackles it with a piecemeal approach towards frequency and voltage stability. As a result, different types of controller topology are currently used to get each electrical parameter within the acceptable tolerance limits The contribution of this paper is to build an integrated controller based on droop control to tackle the two parameters of voltage and frequency stability simultaneously with one controller in a holistic fashion. To achieve this goal of demonstrating integrated control, different control schemes were tested and compared in terms of performance with respect to frequency control. The application of the above mentioned integrated control in a decentralized controller environment like a virtual power plant (VPP) was also demonstrated. The testing and design of the control schemes and BESS was done via benchmark models built for real time digital simulation (RTDS). The results show that the control schemes employed in the BESS can effectively contribute towards providing ancillary services in a holistic manner.