Units or values for the above physical quantities are as follows:

N:  is  number of things, i.e. atoms, molecules or particles

N_A = 6.022 x 10²³ mol^-1

n is number of moles. Unit:  mol

m is mass. Unit: g

M is the molar mass (molecular mass, atomic mass or formula mass - older designations: molecular weight, atomic weight.)  Units g mol^-1

ρ is the density usually with units of g mL^-1 or equilantly kg L^-1

ν is the reaction stoichiometric number (coefficients used in the balanced reaction) and is an exact number.

C in the concentration in molarity.  Units:  mol L^-1 or sometimes represented with small cap M: "M"

V is volume.  For density this is usually mL but for molarity this is L!