how many tirthankara in each ara
In Jain cosmology, there are 24 Tirthankaras in each half-cycle of time (ara). A full wheel of time has two halves (utsarpiṇī and avasarpiṇī), so across a complete cycle there are 48 Tirthankaras in total. The present half-cycle (avasarpiṇī) begins with Rishabhanatha and ends with Mahavira as the 24th Tirthankara. The count (24 per half-cycle) is the same in both Digambara and Śvetāmbara traditions, though the exact names and details for a few Tirthankaras may vary slightly between the two traditions.