To engage in foreign interference is to meddle in something that does not concern you. Therefore, if the Indian government tries to get you to change your position while you're a candidate in a federal leadership race, I would say the Indian government is meddling in something that does not concern it. It shouldn't be allowed to do that. Similarly, if a Quebec municipality wants to participate in a court challenge in Quebec, that's fine.
Conversely, if an Ontario municipality participates in a court challenge in Quebec, I see it as interference. If you can't see the difference, it makes me wonder whether you're able to do so when Indian authorities are involved. That worries me, but you tell me.