We estimate the effect of the tensor parity nonconserving (PNC) interaction in the ¹⁸¹TaO⁺ molecular cation. It can be used to probe the unknown quadrupole distribution of the neutrons inside the Ta nucleus. To this end, we evaluate the constant which characterizes this interaction using the relativistic Fock space coupled cluster theory for electronic structure modelling. The ³Δ₁ state of the TaO⁺ cation which can be used to measure the PNC effect is found to be the ground one in agreement with the previous theoretical study.