If it's a ferplast or midwest or similar, then you can put it on a table. But i'm not sure how that would stop your boy pulling on the bars. There's a thread somewhere about biting if you do a search. Maybe read through that as well and see.
I have all of mine up on tables from Ikea.
Once you have the dimensions of the cage then go online and look at table tops until you find one that is slightly larger than your cage, and will fit into the space you have.
However please be aware that whilst this may keep them safe in the short term, it could actually cause a bigger fall from a greater height if your son works out how to pull the cage off the new table.
I underdstand that it is difficult with young children, but you also need to work on keeping him away from the piggies cage unless he is supervised so you can make sure he understands the dangers of pulling their cage over (for both him and the piggies).
If you have a ferplast cage then pets at home and a few other places online sell a metal stand on wheels that the cage can be placed on.
I think they only do them for up to the 120cm cage size though, maybe 140.
A table is probably your best bet though as the cage stand isn’t very high, the bottom of my cage is about 1.5-2 feet off the floor. I imagine a table from Ikea would actually be cheaper than the stand for the ferplast cages (paid £35 for mine and I only paid £50 for the cage!)