what is meanig of "collenchyma is found

either as a homogeneous layer or in patches"

"Collenchyma is found either as a homogeneous layer or in patches"

This statement tells you that collenchyma can be found in plants in two ways i.e. either it may be present in a uniform layer of cells or it may be in some parts in patches in order to provide mechanical and structural support that part of the plant.