"Khalistan is our (Sikhs) right," he told reporters here.
Mann said his demand for a separate Sikh homeland was not "unconstitutional".
"Mere demand of Khalistan is no offence," the former IPS officer said and accused the Punjab government of carrying out misleading propaganda against him.
"A defamation case will be filed against the Punjab government officials for defaming me and adequate compensation will be demanded," Mann said.