Aishwarya made several investments in windmills in Maharashtra and Rajasthan, which supplies electricity to millions of people that earns her a steady income every year.
She is also a venture capitalist and keeps investing crores of rupees in startups.
She is on the board of directors of several organizations overseas, like some of those companies which featured in the Panama papers.
Not to mention all the assets she already owns, properties in Dubai, New York, Mumbai, etc. She's invested heavily in real estate.
She is still endorsing top international brands like Longines and L'Oreal which pay her in dollars/euros.
She continues to work in big budget films too (currently working in 500 crore film Ponniyin Selvan, and I'm sure she received a fat pay cheque for it).
https://www.dnaindia.com/india/report-maharashtra-wind-generation-brings-windfall-for-aishwarya-rai-bachchan-2706191
https://economictimes.indiatimes.com/tech/funding/aishwarya-rai-bachchan-invests-in-healthtech-startup-possible-as-part-of-a-larger-funding-round/articleshow/80346342.cms?from=mdr
https://analyticsindiamag.com/former-miss-world-aishwarya-rai-bachchan-invest-in-iot-startup/
https://www.businesstoday.in/markets/stocks/amtek-auto-skids-on-bse-nse-pays-back-rich-investors-like-aishwarya-rai-david-dhawan-not-jpmorgan/story/225051.html
3