In this study, we consider the generalized \(\eta \) -Ricci soliton (RS, in short) within the framework of a contact metric manifold \(M^{2n+1}\) with \((\varphi , \xi , \eta , g)\) as a contact metric structure satisfying certain conditions on the potential vector field. First, we establish that a compact contact metric admitting a generalized \(\eta \) -RS with potential vector V as an infinitesimal harmonic transformation (IHT, in short) is \(\eta \) -Einstein provide \(\pounds _V(div V)\ge 0\) . Next, we prove that a generalized \(\eta \) -RS whose potential vector field V is parallel with the Reeb vector field and satisfies \(Q\xi = (Trl)\xi \) is \(\eta \) -Einstein. Finally, we have studied the contact metric manifold with \(Q\varphi = \varphi Q\) and admitting a generalized \(\eta \) -RS when its non-zero potential vector field V is a contact vector field, or a projective vector field.