I closed the entrance small with grass and put a small sprinkler on top. How can I replenish nuc with more bees? Nurse bees from stong hive?
Good guess. Rob a few frames of bees and brood from the hive that robbed the nuc. All that missing honey probably means the nuc is without resources so exchange the ravaged frames then move the nuc. I would suggest putting it on top of the robber hive. The big hive will think it is the same hive and the drift back and forth should equal out. This is of course a temporary solution until the nuc gets big enough to expand into a larger box.
I'd make a robber screen. If that fails then wait until the middle of the day and close off the entrance to the screen so the robbers can't leave. After 72 hours they will reorient to that hive and it will be much stronger. :) Without the screen door (the robber screen with the entrance blocked) they might die in the heat. A feeder jar (quart jar with holes) full of water on top would probably help too.