What can you do about air quality at home during bad AQI months?
The realistic levers, in order of effect: keep windows closed during peak pollution hours and ventilate when readings are lower, usually mid-afternoon rather than early morning in winter; run a HEPA purifier sized for the room, checking CADR rather than marketing claims; avoid adding indoor sources, which means not burning incense or candles and using an exhaust fan while cooking; and reduce outdoor exercise on severe days, since exertion multiplies the dose inhaled. Indoor plants do essentially nothing at realistic densities, despite persistent claims. Masks help outdoors only if they are N95-grade and fitted.
Answers
Mid-afternoon ventilation rather than early morning is genuinely counterintuitive and correct for north Indian winters.
The plants point needs repeating every winter. You would need a forest in the living room.