Answer

If you mean simultaneously living Tirthankaras, Jain tradition says the minimum is 20 and the maximum is 170 at one time. ( jainqq.org)

Explanation

• Minimum 20: In the 5 Mahavideha kshetras, there are at least 4 Tirthankaras in each, so the total minimum is 20. ( jainqq.org)
• Maximum 170: The maximum occurs when there is 1 Tirthankara in each of the 32 vijayas of each of the 5 Mahavidehas, plus 1 in each of the 5 Bharatas and 5 Airavatas, which makes 170 total. ( jainqq.org)

Spiritual Understanding

This shows that in Jain cosmology, the path of liberation is always present somewhere in the universe. Even when one region has no active Tirthankara, other regions can still have living Tirthankaras guiding souls. ( jainqq.org)

Takeaway

So the short answer is: minimum 20, maximum 170 living Tirthankaras at a time in Jain cosmology. ( jainqq.org)