The observation of large intrinsic anomalous Hall conductivity (AHC) in the noncollinear antiferromagnetic phase of the Weyl semimetal Mn₃⁢Sn generates enormous interest in uncovering the entanglement between the real-space magnetic ordering and the momentum-space band structure. Previous studies show that changes in the magnetic structure induced by the application of hydrostatic and chemical pressure can significantly affect the AHC of the Mn_3+𝑥⁢Sn_1−𝑥 system. Here, we employ the muon spin relaxation/rotation (𝜇^+⁢SR) technique to systematically investigate the evolution of different magnetic states in the Mn_3+𝑥⁢Sn_1−𝑥 as a function of hydrostatic and chemical pressure. We find two muon sites experimentally, which is also supported by our ab initio calculations. Our 𝜇⁺⁢SR experiments affirm that the 𝑥=0.05 compound exhibits a commensurate magnetic state throughout the magnetically ordered phase below the Neel temperature 𝑇_𝑁≈420 K in ambient pressure. In contrast, we observe an incommensurate magnetic state below 𝑇_𝐼⁢𝐶∼175 K when a hydrostatic pressure of 1.5 GPa is applied. A similar transition from the commensurate to incommensurate state is also found with chemical pressure for 𝑥=0.04 and 𝑥=0.03, using 𝜇⁺⁢SR and elastic neutron scattering experiments. Using band structure calculations, we have shown the emergence of Fermi nesting in Mn₃⁢Sn and the subsequent development of incommensurate magnetic ordering under hydrostatic/chemical pressure.