JEE Main 2015 · 11 Apr · Shift 1, Chemistry question 49

$\ce{[FeF6]^3-}$: $\ce{Fe^3+}$ is $d^5$, and with the weak-field $\ce{F-}$ it is high spin, $t_{2g}^3e_g^2$. Both sets are evenly (half) filled.

The others:

• $\ce{[CoF6]^3-}$ is $t_{2g}^4e_g^2$.
• $\ce{[Co(NH3)6]^2+}$ is $t_{2g}^5e_g^2$.
• $\ce{[Mn(CN)6]^4-}$ is $t_{2g}^5$.