Stereoisomers

(Considering that all isomers satisfy the given conditions) Since given compound produces pink colour with neutral FeCl₃. So, it must have at least one –OH group attached to benzene ring.
Also, given compound is optically active, it means it should have a chiral centre, which is only possible when it has –CH(OH)CH_3.
DBE (Double bond equivalent) of C₈H₁₀O₂ is

=

=
So, total isomeric structures = 6