There is no legal requirement for Council to take questions from anyone. However most councils will set aside time at the start of meetings for the public to make comments / ask questions.So technically they could refuse your question and would not be breaching any laws. But i doubt they will be taking your ID and cross checking you against the electoral roll before you ask a question. If it's clear to them that you are from outside the parish then it would be down to the councillors whether they wanted to answer your question or not.
Model standing orders state "Members of the public may make representations, answer questions and give evidence at a meeting which they are entitled to attend in respect of the business on the agenda". So if the PC has adopted the model standing orders then yes you should be able to speak. All members of the public are entitled to attend regardless of whether its your parish or not.