It is possible to check Air India flight status without knowing the flight number. You can use the “By Route” option on the Air India website
How To Check Flight Status with Air India
Air India check-in: Web, Mobile, Kiosk and City
Check-in online at Air India is available 24 hours before departure, and up to 2 hours before departure for all domestic and international passengers. Air India’s web check-in service lets passengers print out their boarding passes and select their seats through the Air India website.