Though it is not right for any country to interfere in the internal policies, management and governance of another sovereign country, it happens covertly and overtly.
The reason are defence and territorial safety, prevention of refugee exodus, commercial interest, interest to have a leadership sympathetic to that country's interests.
Such interference also happens due to internal pressures arising in that country to. In the case of Canada, there is a sizeable and influential section of Sikh population. This section has political and economical clout and influence there. So it is Canada's political selfish interest to please their domestic Sikh population.
Apart from this Canada is slowly promoting anti-India interest and pumping funds to nourish anti-India interests.
Recently there was a report about Canda's IDRC(International Development Research Centre) funding a 'research study' in India and coming out against India's Milk industry. That was clearly an anti-India strategy to hit India's economy- as India is the top Milk producer in the world now.
India has to be very alert against such outside interests and interferences. They pamper, promote and protect the anti-national interest in this country too.