Mangrove forest plays a crucial role in coastal protection, nutrient cycling, and aquatic estuarine life as well as coastal livelihoods in tropical coastal habitats and is capable of providing substantial food safety. Despite having high importance of the mangrove ecosystem, mangrove biodiversity is declining rapidly all over due to anthropogenic activities. Moreover, mangrove forests, which is seen to be under threat from the historical and degrading future habitat and rise in sea-level rise. In this chapter through the secondary literature review, we will analyze how mangrove as nature-based solutions helps to protect the restoration of forests and can assist to diminish the tolls of floods and landslides, facilitating tackling droughts, and protecting from cyclone, and salinity. The scope of this chapter was to study the patterns of mangrove abundance that are seen to be NBS and the chapter will be furthermore focusing greatly on the diversity and functions in the Sundarbans. The study will be based on different levels keeping an eye on the depletion of mangroves by the rise in the sea level and erosion of the coasts. In Abidjan and Lagos in West Africa, Sundarbans, Bangladesh, Mumbai, and Karachi in South Asia, Wenzhou in East Asia, Cebu, Denpasar in Southeast Asia, Miami in the USA, and Cancun in Mexico, the mangrove forest protect and make safe to the inhabitants to remain safe from the cyclone and flooding each year, facilitating to avoid damage to property each year. So, nature-based solutions (NBS), as an activity for protection, sustainable management, and restoration of natural or ecosystems going through modification, deal with obstacles of the society efficiently and adjustably, at the same time facilitating human welfare and positive output from biodiversity preservation efforts. Nature-based solutions are reinforced by advantages that emanate from healthy ecosystems. They focus on key difficulties, such as climate change, catastrophe threat lessening, food and water safety, biodiversity damage, and human well-being, and are crucial for ensuring sustainability for economic progress.