If you are genuinely apprehensive of being arrested for a non-bailable offence, you can apply for anticipatory bail even before a First Information Report (FIR) is filed. The court will consider the reasonableness of your apprehension based on specific facts. While a threat of legal action from a family member may not immediately warrant an anticipatory bail application, it's advisable to consult with a legal professional to assess the situation and understand your options.