Counter of entities

is it possible to create a counter of the number of entities in the radius of a TC?

Yes, usually you can get the building privilege by using GetBuilding and there are fields like buildingBlocks and decayEntities if I am not mistaken.

I can only see the number of entities on the whole server with :
"var Convar = ConVar.Admin.ServerInfo();
int EntCount = Convar.EntityCount;"