The first thing I would do is try organize a game possibly. A game where each round kids who win said game, get to play with toys on one side of the area, while the other kids get to sing songs, tell jokes, etc. (if they are allowed to do this)
Maybe you could create a song.
This song would remind kids to not touch each other and to not take things out of others hands.
I am unsure of the age group so my answers may not be great depending on the age, but I’m assuming they are toddlers.
Another solution is buying more toys? Although that could get pricey depending on how many kids there are. Maybe you could also have “shifts” where one group of kids goes outside and another goes in. When the group that was outside comes in, you switch. (If that makes sense.)
The kids inside could read, or sing, etc.