got a help note from the side effects help team here is it
The “found_overlap” is a reserved attribute that is used by the solver to keep track of a state, but doesn't really give any useful information to the user.
From the rbdpackedobject help:
http://www.sidefx.com/docs/houdini/nodes/dop/rbdpackedobject.html#reserved-solver-attributes [
www.sidefx.com]
“When the solver sees an object for the first time, it checks whether that object is initially overlapping with any other objects in the simulation and prevents any such pairs of objects from being forced apart. This value is used by the solver to determine whether it has performed this process for the object on a previous frame.”
In other words, this value is a flag to tell the bullet solver if it should perform the overlapping check or not, it is not intended to tell the user if an object is currently overlapping. At object creation, this flag is set to 0, so the solver performs the overlap check, and flips the flag to 1, so in all subsequent frames, the overlap check doesn't have to be performed.
I hope this will help the other people like me who is confused.