Toluene when refluxed with \(Br_2\) in the presence of light mainly gives

Benzyl bromide

The correct answer is option 2.Benzyl bromide.

The free radical substitution reaction of toluene with bromine in the presence of light is a typical example of a side-chain substitution reaction. The methyl group on the toluene molecule is a benzylic radical, which is more stable than a normal alkyl radical. This makes the methyl group more reactive towards bromine radicals, and the bromination reaction is more likely to occur at the side chain.

In the presence of \(FeBr_3\), the bromine radicals are generated in situ, and the reaction is more selective towards the benzene ring. This is because \(FeBr_3\) is a Lewis acid, and it can activate the benzene ring by abstracting a hydrogen atom. This makes the benzene ring more electron-rich, and it is more likely to be attacked by the bromine radicals.

Therefore, the free radical substitution reaction of toluene with bromine in the presence of light is a side-chain substitution reaction, while the reaction in the presence of \(FeBr_3\) is an electrophilic substitution reaction.