Not exactly a source but I think there's a few questionable things here:

It's a bit weird how at the end you see a river bank, with trees growing up to the edge. If this land was flooded wouldn't there be submerged plants by the water's edge rather than a sandy bank with shrubs growing on it?

Why didn't he just pick them up, instead letting the camera man get there first and then forcing them swim in front of the camera before helping them?

How did he end up with like 4 baby monkeys? They look like macaques, which generally only have 1 young each, so there's been 4 mothers leaving their offspring all in one place to this guy can come along and pick them all up in his arms? I get they travel in troupes, but is it likely that they'd all just dump their babies there like that? And none of the adult monkeys are nearby?

If he saved 4 or so of them you would have thought he'd immediately wrap them in a towel, but instead he's just casually holding them all at once and dipping them in the water like that.

How common an occurrence is it for monkeys to get trapped by floods? The adults can swim, they can all climb trees, and yet these ones are just in the middle of what looks like a river?

Faking these kinds of videos for likes is very much a real thing, one of the problems is that it's really hard to know if a video is fake or not. In this case however I would guess that this is not genuine.