The article presents the case study of ‘Bombay Mothers and Children Welfare Society’, a non-governmental organisation (NGO), working for the welfare of the people primarily in the area of health, education and vocational training, in both, urban and rural areas of Maharashtra (India). Following a qualitative approach, the article aims to understand the challenges encountered by the organisation due to uncertainties induced by the COVID-19 pandemic situation in India and its responses. The study shows that innovative business strategy and participatory-public-philanthropy-person (PPPP) model of sustenance helped the organisation to transform it into a ‘sustainable organisation’. Several long-term measures undertaken with its focus on innovation, stakeholders’ engagement for strategic decisions, community participation, collaboration, and business-like behaviour enabled the organisation to deal with the uncertainties in ‘normal times’. The legacy of good work done by the organisation helped it to gain the trust of all the stakeholders involved. During the COVID-19 crisis, the organisation undertook several short-term measures immediately to respond to the situation and received unconditional support from the staff and also from the community. The outcome was organisation and community resilience, which helped them to deal with the uncertainties in normal times as well as emergency/crisis situation. This article developed a framework for the NGO to deal with uncertainties for achieving their mission during a crisis situation like COVID-19. A combination of long-term and short-term measures, and its focus on innovative business strategy and PPPP model of sustenance, is the clear reflection of the entrepreneurial approach adopted for community development and decisions made by the leader of the NGO played critical role. Thus, the study suggests to follow ‘judgement-based approach towards entrepreneurship’ for understanding NGOs’ actions in crisis situation. The findings provide learnings for NGOs, interested in creating sustainable social organisation, and help them to prepare better to deal with uncertainties during a crisis situation.