KM3NeT/ORCA is an underwater neutrino telescope currently under construction in the Mediterranean Sea, with the goal of measuring atmospheric neutrino oscillation parameters and determining the neutrino mass ordering. KM3NeT/ORCA can additionally provide constraints on physics beyond the Standard Model which could appear through strong matter effects, such as the neutrino Non-Standard Interactions (NSIs). This work reports on the results of the NSIs search with the final dataset of ORCA6, the first configuration of ORCA with six detection units, which uses 433 kton-years of exposure and improved calibration, reconstruction and selection methods compared to previous works. The obtained bounds at 90% CL, $|\varepsilon_{\mu\tau} | \leq 5.5 \cdot 10^{-3}$, $|\varepsilon_{e\tau} | \leq 7.8 \cdot 10^{-2}$, $|\varepsilon_{e\mu} | \leq 5.8 \cdot 10^{-2}$ and $-0.015 \leq \varepsilon_{\tau\tau} - \varepsilon_{\mu\mu} \leq 0.016$, are comparable to the current most stringent limits on any NSIs parameter.