Balance the chemical equation got the reaction of benzene and hydrogen to form cyclohexane

C₆H₆ + 3H₂ → C₆H₁₂

Benzene + 3 molecules of hydrogen = cyclohexane

So essentially what happens is that benzene contains three double bonds and when reacted with hydrogen then these three double bonds can be broken and the hydrogen bond to the tetravalent carbon to restore its for bonds forming cyclohexane