In which nucleophilic aromatic substitution rate is faster m-fluoronitrobenzene or p-fluoronitrobenzene?
The rate of reaction depends on stability of intermediate. The given reaction follows $\ce{S_N2Ar}$ mechanism through &quot;Meisenheimer intermediate&quot;. So, the stability of &quot;Meisenheimer&quot; primarily drives the reaction.

ortho and para isomer are almost same except their position, which is the main reason why is the former reacts much slowly than the latter.

In the ortho isomer, the negative charge of the ring isn't delocalised with $\ce{NO2}$, whereas in the para isomer, it is delocalised, as seen in the following image,

(Source: Master Organic Chemistry)