Hi @SaeranVasanthakumar getting pressure is simple enough, you simply assign probes at the center of the openings, usually on or near the surface itself (examples of applications, some while running the simulation https://cfd.direct/openfoam/user-guide/graphs-monitoring/).
Another a bit more involved way is to use the actual (.stl) surface of each opening from Rhino and sample values over it (eg. average pressure, velocity, etc. over the surface). Or you can use the same technique to sample directly volumetric flow (if this is an actual opening where inflitration happpens (see 6.2.1.2 here).
Kind regards,
Theodore.