Use a good quality detergent to get rid of that stain.You can use washing soda also.Ink stains are not that much tough to remove.If your couch is of leather ,it will definitely work .In case it's a velvet couch ,you have to dip a piece of cotton in a solution of any detergent and rub over the stains with soft hands,then when the stains are removed dip another piece of cotton into water and rub over the stain.