South Asia is home to well over one fifth of the world’s population, making it most densely populated region of the world with the highest regional Global Hunger Index leading to food insecurity. IPCC fifth assessment report shows regional effects of climate change likely to create major impacts on water, energy and food security. Due to the impacts of climate change, many regions are expected to see a decline in food productivity, with the largest numbers of food-insecure people in South Asia. Climate change will challenge water supply issues in South and South East Asia and may adversely affect agricultural and livestock sustainability. The objective of project is to model how projected climate change scenarios will spatially and temporally impact cereal production, a dietary staple for billions of people in South Asia. Climate change scenarios of temperature and precipitation will be constructed using state of the art weather generator approach for the first time for South Asia. Impact assessment with climate smart approaches using simulation models and devising climate change adaptation strategies for integration in policy making will help build resilience in water efficient agriculture and food security. Main focus of the project will be to develop reliable local scale climate change information with statistical downscaling techniques using Weather generators. This information will then be applied to crop water models to simulate yield response to water for climate change impact assessment. Assessment of water use productivity and water-limited attainable yields of cereal crops, wheat and rice will be done for different agro ecological zones under present and future climate change scenarios. Climate change adaptations strategies for sustainable cereal production will be devised to build resilience in food security by ensuring water efficient staple cereal crop production of south and East Asia.