${\mathrm{K}}_{\mathrm{c}}$ value of a gaseous reversible reaction is 5 mole / lit. If the pressure is increased for this system at equilibrium then

K_C = 5 mole/lit

Units of K_C are (mole/lit)^Δn

Δn = 1

It indictes n_P(g) > n_R (g)

So forward reaction involves increase in volume.

So forward reaction is favoured at low pressure.

High pressure favours backward reaction.