  Quantum state readout is a key requirement for a successful qubit platform.
In this work we demonstrate a high fidelity quantum state readout of a V2
center nuclear spin based on a repetitive readout technique. We demonstrate up
to 99.5$\,\%$ readout fidelity and 99$\,\%$ for state preparation. Using this
efficient readout we initialise the nuclear spin by measurement and demonstrate
its Rabi and Ramsey nutation. Finally, we use the nuclear spin as a long lived
memory for quantum sensing application of weakly coupled diatomic nuclear spin
bath.
