[en] In recent years, several efforts have been made to understand the reaction dynamics of incomplete fusion (ICF) processes in heavy-ion (HI) collisions at energies from near the Coulomb barrier to well above it (i.e. ≈ 4-7 MeV/nucleon). Generally, at these energies, complete fusion (CF) process is one of the dominant mode of reaction to the total fusion (TF) cross-section. However, recent experimental data shows a significant observation of ICF reactions at these energies and has created a resurgent interest. In the present work, an attempt has been made to understand the role of projectile structure on ICF reaction dynamics at low energies. The ICF probability for the systems, ^12,13C + ¹⁶⁹Tm, ¹⁶O + ¹⁶⁹Tm and ¹⁹F + ¹⁶⁹Tm, which involve different projectiles on the same target, has been deduced from the experimentally measured excitation functions (EFs)