Right to Abode

I'm trying to obtain my right to abode status need some advice. Both my parents were born in a colony of the UK they immigrated to Canada as landed immigrants with UK passports (which I have). I was born before the country of their birth became independant and before they officially became Canadian citizens. Would I be eligible for RTA status? Can I apply while in the UK? My visitors visa expires at the end of June and I'm looking for ways to remain in the country.
Thanks for the help!