Oxygen atom needs ___________ electrons to attain octet in its valence shell

Oxygen atomic number $(\text{Z}=8)$

Electronic configuration $\to \frac{1{\text{s}}^2}{\text{K}}\frac{2{\text{s}}^{2}2{\text{p}}^4}{\text{L}}$

Oxygen gain ‘2’ electrons to attain nearest noble gas electronic configuration.