Ancient Origins has an article of how the Hindu Flood Legend is very similar to the story of Noah found in Genesis. You can read the story by following the link here. This Hindu story is not really a problem for Christians since it stands to reason that all the nations of the earth descended from Noah and his three sons after the flood. We would expect there to be stories of the flood coming from every tribe and nation. It is confirmation of the flood.
The temptation on the part of many of the critics of Christianity is to say that Moses, who wrote about the story of Noah in Genesis, was merely capitalizing on the the story found in other traditions. That is partly true.
Moses was, by God’s hand, setting the record straight for God’s people. Remember his original audience are the people he lead out of Egypt during the exodus. He is writing to them, and us, showing their origins and how it was that they came to be. When he gets to the story of Noah, he is telling the story from God’s point of view. We see this confirmation from the article cited above.
According to the Hindu legend, it is Noah (Manu) who saves the people from the flood. But according to Genesis, it is God who saves Noah and his family through the flood. The true story is of God’s hand in delivering his people. It is about God’s mercy to Noah, not Noah’s cleverness to escape the coming deluge.
These small facts are actually confirmation to us that the Bible truly is God’s word written by God through apostles and prophets. What I mean by that is that when man writes a story of an event, as in the case of the Hindus, the central point is the man and how heroic he was. But when God writes the story, the central point is how wicked the people are, justly deserving destruction, yet God shows mercy to a few.
We can take this same truth and apply it to the gospels as well. If it is man alone writing the gospels, then Peter and the apostles would have all turned out to be heroes in the story. But they are far from heroes. In all four gospels, we see that Peter denied the LORD three times. Not once, did he look good in the story. This is true because the writers of the gospel are not just men writing the historical accounts, but that God’s Spirit carried them along to write the history as it took place.
Given this general principle of Scripture, we should expect similarities in the Genesis account of the flood and other accounts found in other cultures. We might even see that these other accounts predate the writing of the Genesis account. But that is not a problem when we see that it was God’s purpose to tell His people how the flood actually came about. It was not just some natural event, but God’s judgment on the wickedness of the earth. In His grace and mercy, He spared Noah and his sons. And, in His grace and mercy, He gave us the true account of the flood through His prophet Noah so that we may know the God of all creation, who stands over and above all the gods of the pagan cultures. We need to understand this reality about God today just as much as the Israelites did in coming out of Egypt. Our God is the God of all creation, and the final Judge of it as well. Yes, other cultures have a history of the flood, but it is only when we understand that history from God’s perspective that we catch a greater glimpse of God’s purpose through the flood: a glorious show of His mercy and grace toward His people.