The correct answer is Patliputra.

• The First Jain assembly was held in 300 BC at Patliputra (present Patna).

Key Points

• This meeting took place during the reign of Chandragupta Maurya.
• This meeting took place under the chairmanship of Sthoolabhadr. 
• In this part of the body of Jainism, 12 parts were edited.
• In the first Jain assembly, the Jain religion was divided into two parts Digambar and Shwetambar.​

Tirthankar: 

• ​A Tirthankar is referred to as ‘teaching god’ or ‘Ford Maker’ in Jainism. 
• In Jainism, it is believed that each cosmic age produces 24 Tirthankaras.
• The Tirthankaras in the art are shown in the Kayotsarga pose (dismissing the body).
• The 24 Tirthankaras are distinguished from each other by the symbolic colours or emblems.

Additional Information

• Rishabhanatha was the first Jain Tirthankara.
• Ajitnath was the second Jain Tirthankara.
• Sumatinath was the fifth Jain Tirthankara.
• Abhinandananatha was the fourth Jain Tirthankara.
• Parshwanath was the 23rd Jain Tirthankara.
• Mahavira was the 24th Jain Tirthankara.